diff --git a/nonebot/__init__.py b/nonebot/__init__.py
index 6e71bfa9..9c8d62ac 100644
--- a/nonebot/__init__.py
+++ b/nonebot/__init__.py
@@ -26,7 +26,9 @@
 - `load_builtin_plugin` => {ref}``load_builtin_plugin` <nonebot.plugin.load.load_builtin_plugin>`
 - `load_builtin_plugins` => {ref}``load_builtin_plugins` <nonebot.plugin.load.load_builtin_plugins>`
 - `get_plugin` => {ref}``get_plugin` <nonebot.plugin.plugin.get_plugin>`
+- `get_plugin_by_module_name` => {ref}``get_plugin_by_module_name` <nonebot.plugin.plugin.get_plugin_by_module_name>`
 - `get_loaded_plugins` => {ref}``get_loaded_plugins` <nonebot.plugin.plugin.get_loaded_plugins>`
+- `get_available_plugin_names` => {ref}``get_available_plugin_names` <nonebot.plugin.plugin.get_available_plugin_names>`
 - `export` => {ref}``export` <nonebot.plugin.export.export>`
 - `require` => {ref}``require` <nonebot.plugin.load.require>`
 
@@ -284,5 +286,7 @@ from nonebot.plugin import on_shell_command as on_shell_command
 from nonebot.plugin import get_loaded_plugins as get_loaded_plugins
 from nonebot.plugin import load_builtin_plugin as load_builtin_plugin
 from nonebot.plugin import load_builtin_plugins as load_builtin_plugins
+from nonebot.plugin import get_plugin_by_module_name as get_plugin_by_module_name
+from nonebot.plugin import get_available_plugin_names as get_available_plugin_names
 
 __autodoc__ = {"internal": False}
diff --git a/nonebot/plugin/__init__.py b/nonebot/plugin/__init__.py
index c7b48c3b..6358a884 100644
--- a/nonebot/plugin/__init__.py
+++ b/nonebot/plugin/__init__.py
@@ -35,14 +35,77 @@ FrontMatter:
     description: nonebot.plugin 模块
 """
 
-from typing import List, Optional
+from itertools import chain
+from types import ModuleType
 from contextvars import ContextVar
+from typing import Set, Dict, List, Optional
 
+_plugins: Dict[str, "Plugin"] = {}
 _managers: List["PluginManager"] = []
 _current_plugin: ContextVar[Optional["Plugin"]] = ContextVar(
     "_current_plugin", default=None
 )
 
+
+def _module_name_to_plugin_name(module_name: str) -> str:
+    return module_name.rsplit(".", 1)[-1]
+
+
+def _new_plugin(
+    module_name: str, module: ModuleType, manager: "PluginManager"
+) -> "Plugin":
+    plugin_name = _module_name_to_plugin_name(module_name)
+    if plugin_name in _plugins:
+        raise RuntimeError("Plugin already exists! Check your plugin name.")
+    plugin = Plugin(plugin_name, module, module_name, manager)
+    _plugins[plugin_name] = plugin
+    return plugin
+
+
+def _revert_plugin(plugin: "Plugin") -> None:
+    if plugin.name not in _plugins:
+        raise RuntimeError("Plugin not found!")
+    del _plugins[plugin.name]
+
+
+def get_plugin(name: str) -> Optional["Plugin"]:
+    """获取已经导入的某个插件。
+
+    如果为 `load_plugins` 文件夹导入的插件，则为文件(夹)名。
+
+    参数:
+        name: 插件名，即 {ref}`nonebot.plugin.plugin.Plugin.name`。
+    """
+    return _plugins.get(name)
+
+
+def get_plugin_by_module_name(module_name: str) -> Optional["Plugin"]:
+    """通过模块名获取已经导入的某个插件。
+
+    如果提供的模块名为某个插件的子模块，同样会返回该插件。
+
+    参数:
+        module_name: 模块名，即 {ref}`nonebot.plugin.plugin.Plugin.module_name`。
+    """
+    splits = module_name.split(".")
+    loaded = {plugin.module_name: plugin for plugin in _plugins.values()}
+    while splits:
+        name = ".".join(splits)
+        if name in loaded:
+            return loaded[name]
+        splits.pop()
+
+
+def get_loaded_plugins() -> Set["Plugin"]:
+    """获取当前已导入的所有插件。"""
+    return set(_plugins.values())
+
+
+def get_available_plugin_names() -> Set[str]:
+    """获取当前所有可用的插件名（包含尚未加载的插件）。"""
+    return {*chain.from_iterable(manager.available_plugins for manager in _managers)}
+
+
 from .on import on as on
 from .manager import PluginManager
 from .export import Export as Export
@@ -61,7 +124,6 @@ from .on import CommandGroup as CommandGroup
 from .on import MatcherGroup as MatcherGroup
 from .on import on_fullmatch as on_fullmatch
 from .on import on_metaevent as on_metaevent
-from .plugin import get_plugin as get_plugin
 from .load import load_plugins as load_plugins
 from .on import on_startswith as on_startswith
 from .load import load_from_json as load_from_json
@@ -69,5 +131,4 @@ from .load import load_from_toml as load_from_toml
 from .on import on_shell_command as on_shell_command
 from .load import load_all_plugins as load_all_plugins
 from .load import load_builtin_plugin as load_builtin_plugin
-from .plugin import get_loaded_plugins as get_loaded_plugins
 from .load import load_builtin_plugins as load_builtin_plugins
diff --git a/nonebot/plugin/load.py b/nonebot/plugin/load.py
index 7e762b69..a241804f 100644
--- a/nonebot/plugin/load.py
+++ b/nonebot/plugin/load.py
@@ -10,10 +10,10 @@ from typing import Set, Iterable, Optional
 
 import tomlkit
 
-from . import _managers
 from .export import Export
+from .plugin import Plugin
 from .manager import PluginManager
-from .plugin import Plugin, get_plugin
+from . import _managers, get_plugin, _module_name_to_plugin_name
 
 
 def load_plugin(module_path: str) -> Optional[Plugin]:
@@ -128,7 +128,7 @@ def load_builtin_plugin(name: str) -> Optional[Plugin]:
     return load_plugin(f"nonebot.plugins.{name}")
 
 
-def load_builtin_plugins(*plugins) -> Set[Plugin]:
+def load_builtin_plugins(*plugins: str) -> Set[Plugin]:
     """导入多个 NoneBot 内置插件。
 
     参数:
@@ -154,7 +154,7 @@ def require(name: str) -> Export:
     异常:
         RuntimeError: 插件无法加载
     """
-    plugin = get_plugin(name.rsplit(".", 1)[-1])
+    plugin = get_plugin(_module_name_to_plugin_name(name))
     if not plugin:
         manager = _find_manager_by_name(name)
         if manager:
diff --git a/nonebot/plugin/manager.py b/nonebot/plugin/manager.py
index 7e8b2826..4b85111a 100644
--- a/nonebot/plugin/manager.py
+++ b/nonebot/plugin/manager.py
@@ -19,23 +19,52 @@ from typing import Set, Dict, List, Union, Iterable, Optional, Sequence
 from nonebot.log import logger
 from nonebot.utils import escape_tag
 
-from . import _managers, _current_plugin
-from .plugin import Plugin, _new_plugin, _confirm_plugin
+from .plugin import Plugin
+from . import (
+    _managers,
+    _new_plugin,
+    _revert_plugin,
+    _current_plugin,
+    _module_name_to_plugin_name,
+)
 
 
 class PluginManager:
+    """插件管理器。
+
+    参数:
+        plugins: 独立插件模块名集合。
+        search_path: 插件搜索路径（文件夹）。
+    """
+
     def __init__(
         self,
         plugins: Optional[Iterable[str]] = None,
         search_path: Optional[Iterable[str]] = None,
     ):
-
         # simple plugin not in search path
         self.plugins: Set[str] = set(plugins or [])
         self.search_path: Set[str] = set(search_path or [])
+
         # cache plugins
-        self.searched_plugins: Dict[str, Path] = {}
-        self.list_plugins()
+        self._third_party_plugin_names: Dict[str, str] = {}
+        self._searched_plugin_names: Dict[str, Path] = {}
+        self.prepare_plugins()
+
+    @property
+    def third_party_plugins(self) -> Set[str]:
+        """返回所有独立插件名称。"""
+        return set(self._third_party_plugin_names.keys())
+
+    @property
+    def searched_plugins(self) -> Set[str]:
+        """返回已搜索到的插件名称。"""
+        return set(self._searched_plugin_names.keys())
+
+    @property
+    def available_plugins(self) -> Set[str]:
+        """返回当前插件管理器中可用的插件名称。"""
+        return self.third_party_plugins | self.searched_plugins
 
     def _path_to_module_name(self, path: Path) -> str:
         rel_path = path.resolve().relative_to(Path(".").resolve())
@@ -44,48 +73,51 @@ class PluginManager:
         else:
             return ".".join(rel_path.parts[:-1] + (rel_path.stem,))
 
-    def _previous_plugins(self) -> List[str]:
+    def _previous_plugins(self) -> Set[str]:
         _pre_managers: List[PluginManager]
         if self in _managers:
             _pre_managers = _managers[: _managers.index(self)]
         else:
             _pre_managers = _managers[:]
 
-        return [
-            *chain.from_iterable(
-                [
-                    *map(lambda x: x.rsplit(".", 1)[-1], manager.plugins),
-                    *manager.searched_plugins.keys(),
-                ]
-                for manager in _pre_managers
-            )
-        ]
+        return {
+            *chain.from_iterable(manager.available_plugins for manager in _pre_managers)
+        }
+
+    def prepare_plugins(self) -> Set[str]:
+        """搜索插件并缓存插件名称。"""
 
-    def list_plugins(self) -> Set[str]:
         # get all previous ready to load plugins
         previous_plugins = self._previous_plugins()
         searched_plugins: Dict[str, Path] = {}
-        third_party_plugins: Set[str] = set()
+        third_party_plugins: Dict[str, str] = {}
 
+        # check third party plugins
         for plugin in self.plugins:
-            name = plugin.rsplit(".", 1)[-1]
+            name = _module_name_to_plugin_name(plugin)
             if name in third_party_plugins or name in previous_plugins:
                 raise RuntimeError(
                     f"Plugin already exists: {name}! Check your plugin name"
                 )
-            third_party_plugins.add(plugin)
+            third_party_plugins[name] = plugin
 
+        self._third_party_plugin_names = third_party_plugins
+
+        # check plugins in search path
         for module_info in pkgutil.iter_modules(self.search_path):
+            # ignore if startswith "_"
             if module_info.name.startswith("_"):
                 continue
+
             if (
-                module_info.name in searched_plugins.keys()
+                module_info.name in searched_plugins
                 or module_info.name in previous_plugins
                 or module_info.name in third_party_plugins
             ):
                 raise RuntimeError(
                     f"Plugin already exists: {module_info.name}! Check your plugin name"
                 )
+
             module_spec = module_info.module_finder.find_spec(module_info.name, None)
             if not module_spec:
                 continue
@@ -94,17 +126,27 @@ class PluginManager:
                 continue
             searched_plugins[module_info.name] = Path(module_path).resolve()
 
-        self.searched_plugins = searched_plugins
+        self._searched_plugin_names = searched_plugins
 
-        return third_party_plugins | set(self.searched_plugins.keys())
+        return self.available_plugins
 
     def load_plugin(self, name: str) -> Optional[Plugin]:
+        """加载指定插件。
+
+        对于独立插件，可以使用完整插件模块名或者插件名称。
+
+        参数:
+            name: 插件名称。
+        """
+
         try:
             if name in self.plugins:
                 module = importlib.import_module(name)
-            elif name in self.searched_plugins:
+            elif name in self._third_party_plugin_names:
+                module = importlib.import_module(self._third_party_plugin_names[name])
+            elif name in self._searched_plugin_names:
                 module = importlib.import_module(
-                    self._path_to_module_name(self.searched_plugins[name])
+                    self._path_to_module_name(self._searched_plugin_names[name])
                 )
             else:
                 raise RuntimeError(f"Plugin not found: {name}! Check your plugin name")
@@ -125,8 +167,10 @@ class PluginManager:
             )
 
     def load_all_plugins(self) -> Set[Plugin]:
+        """加载所有可用插件。"""
+
         return set(
-            filter(None, (self.load_plugin(name) for name in self.list_plugins()))
+            filter(None, (self.load_plugin(name) for name in self.available_plugins))
         )
 
 
@@ -147,9 +191,10 @@ class PluginFinder(MetaPathFinder):
             module_path = Path(module_origin).resolve()
 
             for manager in reversed(_managers):
+                # use path instead of name in case of submodule name conflict
                 if (
                     fullname in manager.plugins
-                    or module_path in manager.searched_plugins.values()
+                    or module_path in manager._searched_plugin_names.values()
                 ):
                     module_spec.loader = PluginLoader(manager, fullname, module_origin)
                     return module_spec
@@ -173,7 +218,11 @@ class PluginLoader(SourceFileLoader):
         if self.loaded:
             return
 
+        # create plugin before executing
         plugin = _new_plugin(self.name, module, self.manager)
+        setattr(module, "__plugin__", plugin)
+
+        # detect parent plugin before entering current plugin context
         parent_plugin = _current_plugin.get()
         if parent_plugin and _managers.index(parent_plugin.manager) < _managers.index(
             self.manager
@@ -181,21 +230,18 @@ class PluginLoader(SourceFileLoader):
             plugin.parent_plugin = parent_plugin
             parent_plugin.sub_plugins.add(plugin)
 
+        # enter plugin context
         _plugin_token = _current_plugin.set(plugin)
 
-        setattr(module, "__plugin__", plugin)
+        try:
+            super().exec_module(module)
+        except Exception:
+            _revert_plugin(plugin)
+            raise
+        finally:
+            # leave plugin context
+            _current_plugin.reset(_plugin_token)
 
-        # try:
-        #     super().exec_module(module)
-        # except Exception as e:
-        #     raise ImportError(
-        #         f"Error when executing module {module_name} from {module.__file__}."
-        #     ) from e
-        super().exec_module(module)
-
-        _confirm_plugin(plugin)
-
-        _current_plugin.reset(_plugin_token)
         return
 
 
diff --git a/nonebot/plugin/on.py b/nonebot/plugin/on.py
index 2340255d..40afd83c 100644
--- a/nonebot/plugin/on.py
+++ b/nonebot/plugin/on.py
@@ -5,7 +5,6 @@ FrontMatter:
     description: nonebot.plugin.on 模块
 """
 import re
-import sys
 import inspect
 from types import ModuleType
 from typing import Any, Set, Dict, List, Type, Tuple, Union, Optional
@@ -41,8 +40,7 @@ def _get_matcher_module(depth: int = 1) -> Optional[ModuleType]:
     if current_frame is None:
         return None
     frame = inspect.getouterframes(current_frame)[depth + 1].frame
-    module_name = frame.f_globals["__name__"]
-    return sys.modules.get(module_name)
+    return inspect.getmodule(frame)
 
 
 def on(
diff --git a/nonebot/plugin/plugin.py b/nonebot/plugin/plugin.py
index 10e43723..658c073b 100644
--- a/nonebot/plugin/plugin.py
+++ b/nonebot/plugin/plugin.py
@@ -6,18 +6,16 @@ FrontMatter:
 """
 from types import ModuleType
 from dataclasses import field, dataclass
-from typing import TYPE_CHECKING, Set, Dict, Type, Optional
+from typing import TYPE_CHECKING, Set, Type, Optional
 
 from nonebot.matcher import Matcher
 
 from .export import Export
+from . import _plugins as plugins  # FIXME: backport for nonebug
 
 if TYPE_CHECKING:
     from .manager import PluginManager
 
-plugins: Dict[str, "Plugin"] = {}
-"""已加载的插件"""
-
 
 @dataclass(eq=False)
 class Plugin(object):
@@ -32,40 +30,10 @@ class Plugin(object):
     manager: "PluginManager"
     """导入该插件的插件管理器"""
     export: Export = field(default_factory=Export)
-    """插件内定义的导出内容"""
+    """**Deprecated:** 插件内定义的导出内容"""
     matcher: Set[Type[Matcher]] = field(default_factory=set)
     """插件内定义的 `Matcher`"""
     parent_plugin: Optional["Plugin"] = None
     """父插件"""
     sub_plugins: Set["Plugin"] = field(default_factory=set)
     """子插件集合"""
-
-
-def get_plugin(name: str) -> Optional[Plugin]:
-    """获取已经导入的某个插件。
-
-    如果为 `load_plugins` 文件夹导入的插件，则为文件(夹)名。
-
-    参数:
-        name: 插件名，即 {ref}`nonebot.plugin.plugin.Plugin.name`。
-    """
-    return plugins.get(name)
-
-
-def get_loaded_plugins() -> Set[Plugin]:
-    """获取当前已导入的所有插件。"""
-    return set(plugins.values())
-
-
-def _new_plugin(fullname: str, module: ModuleType, manager: "PluginManager") -> Plugin:
-    name = fullname.rsplit(".", 1)[-1] if "." in fullname else fullname
-    if name in plugins:
-        raise RuntimeError("Plugin already exists! Check your plugin name.")
-    plugin = Plugin(name, module, fullname, manager)
-    return plugin
-
-
-def _confirm_plugin(plugin: Plugin) -> None:
-    if plugin.name in plugins:
-        raise RuntimeError("Plugin already exists! Check your plugin name.")
-    plugins[plugin.name] = plugin
diff --git a/tests/bad_plugins/bad_plugin.py b/tests/bad_plugins/bad_plugin.py
new file mode 100644
index 00000000..1c84f256
--- /dev/null
+++ b/tests/bad_plugins/bad_plugin.py
@@ -0,0 +1,6 @@
+import nonebot
+
+plugin = nonebot.get_plugin("bad_plugin")
+assert plugin
+
+x = 1 / 0
diff --git a/tests/plugins/_hidden.py b/tests/plugins/_hidden.py
new file mode 100644
index 00000000..2cfffa40
--- /dev/null
+++ b/tests/plugins/_hidden.py
@@ -0,0 +1 @@
+assert False
diff --git a/tests/plugins/export.py b/tests/plugins/export.py
index f7570e92..149b8360 100644
--- a/tests/plugins/export.py
+++ b/tests/plugins/export.py
@@ -3,4 +3,4 @@ from nonebot import export
 
 @export()
 def test():
-    ...
+    return "export"
diff --git a/tests/plugins/nested/__init__.py b/tests/plugins/nested/__init__.py
new file mode 100644
index 00000000..eb4cf3e4
--- /dev/null
+++ b/tests/plugins/nested/__init__.py
@@ -0,0 +1,6 @@
+from pathlib import Path
+
+import nonebot
+
+_sub_plugins = set()
+_sub_plugins |= nonebot.load_plugins(str((Path(__file__).parent / "plugins").resolve()))
diff --git a/tests/plugins/nested/plugins/nested_subplugin.py b/tests/plugins/nested/plugins/nested_subplugin.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/plugins/require.py b/tests/plugins/require.py
index 5764431c..8a9084d3 100644
--- a/tests/plugins/require.py
+++ b/tests/plugins/require.py
@@ -1,8 +1,7 @@
 from nonebot import require
-from plugins.export import test
-
-from .export import test as test_related
 
 test_require = require("export").test
 
-assert test is test_related and test is test_require, "Export Require Error"
+from plugins.export import test
+
+assert test is test_require and test() == "export", "Export Require Error"
diff --git a/tests/test_plugin/test_get.py b/tests/test_plugin/test_get.py
new file mode 100644
index 00000000..0e068643
--- /dev/null
+++ b/tests/test_plugin/test_get.py
@@ -0,0 +1,39 @@
+from typing import TYPE_CHECKING, Set
+
+import pytest
+from nonebug import App
+
+if TYPE_CHECKING:
+    from nonebot.plugin import Plugin
+
+
+@pytest.mark.asyncio
+async def test_get_plugin(app: App, load_plugin: Set["Plugin"]):
+    import nonebot
+
+    # check simple plugin
+    plugin = nonebot.get_plugin("export")
+    assert plugin
+    assert plugin.module_name == "plugins.export"
+
+    # check sub plugin
+    plugin = nonebot.get_plugin("nested_subplugin")
+    assert plugin
+    assert plugin.module_name == "plugins.nested.plugins.nested_subplugin"
+
+    # check get plugin by module name
+    plugin = nonebot.get_plugin_by_module_name("plugins.nested.utils")
+    assert plugin
+    assert plugin.module_name == "plugins.nested"
+
+
+@pytest.mark.asyncio
+async def test_get_available_plugin(app: App):
+    import nonebot
+    from nonebot.plugin import PluginManager, _managers
+
+    _managers.append(PluginManager(["plugins.export", "plugin.require"]))
+
+    # check get available plugins
+    plugin_names = nonebot.get_available_plugin_names()
+    assert plugin_names == {"export", "require"}
diff --git a/tests/test_plugin/test_load.py b/tests/test_plugin/test_load.py
index c0c0c8f6..209ee8e0 100644
--- a/tests/test_plugin/test_load.py
+++ b/tests/test_plugin/test_load.py
@@ -9,27 +9,40 @@ if TYPE_CHECKING:
 
 
 @pytest.mark.asyncio
-async def test_load_plugin(load_plugin: Set["Plugin"]):
+async def test_load_plugin(app: App, load_plugin: Set["Plugin"]):
     import nonebot
+    from nonebot.plugin import PluginManager
 
-    loaded_plugins = set(
+    loaded_plugins = {
         plugin for plugin in nonebot.get_loaded_plugins() if not plugin.parent_plugin
-    )
+    }
     assert loaded_plugins == load_plugin
-    plugin = nonebot.get_plugin("export")
-    assert plugin
-    assert plugin.module_name == "plugins.export"
+
+    # check simple plugin
     assert "plugins.export" in sys.modules
 
-    try:
-        nonebot.load_plugin("plugins.export")
-        assert False
-    except RuntimeError:
-        assert True
+    # check sub plugin
+    assert "plugins.nested.plugins.nested_subplugin" in sys.modules
 
+    # check load again
+    with pytest.raises(RuntimeError):
+        PluginManager(plugins=["plugins.export"]).load_all_plugins()
+    with pytest.raises(RuntimeError):
+        PluginManager(search_path=["plugins"]).load_all_plugins()
+
+    # check not found
     assert nonebot.load_plugin("some_plugin_not_exist") is None
 
 
+@pytest.mark.asyncio
+async def test_bad_plugin(app: App):
+    import nonebot
+
+    nonebot.load_plugins("bad_plugins")
+
+    assert nonebot.get_plugin("bad_plugins") is None
+
+
 @pytest.mark.asyncio
 async def test_require_loaded(app: App, monkeypatch: pytest.MonkeyPatch):
     import nonebot
@@ -47,8 +60,7 @@ async def test_require_loaded(app: App, monkeypatch: pytest.MonkeyPatch):
 @pytest.mark.asyncio
 async def test_require_not_loaded(app: App, monkeypatch: pytest.MonkeyPatch):
     import nonebot
-    from nonebot.plugin import _managers
-    from nonebot.plugin.manager import PluginManager
+    from nonebot.plugin import PluginManager, _managers
 
     m = PluginManager(["plugins.export"])
     _managers.append(m)
@@ -80,10 +92,6 @@ async def test_require_not_declared(app: App):
 @pytest.mark.asyncio
 async def test_require_not_found(app: App):
     import nonebot
-    from nonebot.plugin import _managers
 
-    try:
+    with pytest.raises(RuntimeError):
         nonebot.require("some_plugin_not_exist")
-        assert False
-    except RuntimeError:
-        assert True
diff --git a/tests/test_plugin/test_manager.py b/tests/test_plugin/test_manager.py
new file mode 100644
index 00000000..e5758f78
--- /dev/null
+++ b/tests/test_plugin/test_manager.py
@@ -0,0 +1,12 @@
+import pytest
+from nonebug import App
+
+
+@pytest.mark.asyncio
+async def test_load_plugin_name(app: App):
+    from nonebot.plugin import PluginManager
+
+    m = PluginManager(plugins=["plugins.export"])
+    module1 = m.load_plugin("export")
+    module2 = m.load_plugin("plugins.export")
+    assert module1 is module2