diff --git a/nonebot/__init__.py b/nonebot/__init__.py
index 92d63d75..78f7fc39 100644
--- a/nonebot/__init__.py
+++ b/nonebot/__init__.py
@@ -37,7 +37,7 @@ from nonebot.adapters import Bot
 from nonebot.utils import escape_tag
 from nonebot.config import Env, Config
 from nonebot.log import logger, default_filter
-from nonebot.drivers import Driver, ReverseDriver
+from nonebot.drivers import Driver, ReverseDriver, combine_driver
 
 try:
     _dist: pkg_resources.Distribution = pkg_resources.get_distribution("nonebot2")
@@ -195,6 +195,35 @@ def get_bots() -> Dict[str, Bot]:
     return driver.bots
 
 
+def _resolve_dot_notation(
+    obj_str: str, default_attr: str, default_prefix: Optional[str] = None
+) -> Any:
+    modulename, _, cls = obj_str.partition(":")
+    if default_prefix is not None and modulename.startswith("~"):
+        modulename = default_prefix + modulename[1:]
+    module = importlib.import_module(modulename)
+    if not cls:
+        return getattr(module, default_attr)
+    instance = module
+    for attr_str in cls.split("."):
+        instance = getattr(instance, attr_str)
+    return instance
+
+
+def _resolve_combine_expr(obj_str: str) -> Type[Driver]:
+    drivers = obj_str.split("+")
+    DriverClass = _resolve_dot_notation(
+        drivers[0], "Driver", default_prefix="nonebot.drivers."
+    )
+    if len(drivers) == 1:
+        return DriverClass
+    mixins = [
+        _resolve_dot_notation(mixin, "Mixin", default_prefix="nonebot.drivers.")
+        for mixin in drivers[1:]
+    ]
+    return combine_driver(DriverClass, *mixins)
+
+
 def init(*, _env_file: Optional[str] = None, **kwargs):
     """
     :说明:
@@ -243,12 +272,7 @@ def init(*, _env_file: Optional[str] = None, **kwargs):
             f"Loaded <y><b>Config</b></y>: {escape_tag(str(config.dict()))}"
         )
 
-        modulename, _, cls = config.driver.partition(":")
-        module = importlib.import_module(modulename)
-        instance = module
-        for attr_str in (cls or "Driver").split("."):
-            instance = getattr(instance, attr_str)
-        DriverClass: Type[Driver] = instance  # type: ignore
+        DriverClass: Type[Driver] = _resolve_combine_expr(config.driver)
         _driver = DriverClass(env, config)
 
 
diff --git a/nonebot/drivers/__init__.py b/nonebot/drivers/__init__.py
index 44868897..079534ce 100644
--- a/nonebot/drivers/__init__.py
+++ b/nonebot/drivers/__init__.py
@@ -252,7 +252,13 @@ class ReverseDriver(Driver):
 
 
 def combine_driver(driver: Type[Driver], *mixins: Type[ForwardMixin]) -> Type[Driver]:
-    class CombinedDriver(driver, *mixins, ForwardDriver):  # type: ignore
+    # check first
+    assert issubclass(driver, Driver), "`driver` must be subclass of Driver"
+    assert all(
+        map(lambda m: issubclass(m, ForwardMixin), mixins)
+    ), "`mixins` must be subclass of ForwardMixin"
+
+    class CombinedDriver(*mixins, driver, ForwardDriver):  # type: ignore
         @property
         def type(self) -> str:
             return (
diff --git a/nonebot/drivers/_block_driver.py b/nonebot/drivers/_block_driver.py
index afd7f8b3..0e8f34f8 100644
--- a/nonebot/drivers/_block_driver.py
+++ b/nonebot/drivers/_block_driver.py
@@ -4,9 +4,9 @@ import threading
 from typing import Set, Callable, Awaitable
 
 from nonebot.log import logger
+from nonebot.drivers import Driver
 from nonebot.typing import overrides
 from nonebot.config import Env, Config
-from nonebot.drivers import ForwardDriver
 
 STARTUP_FUNC = Callable[[], Awaitable[None]]
 SHUTDOWN_FUNC = Callable[[], Awaitable[None]]
@@ -16,11 +16,7 @@ HANDLED_SIGNALS = (
 )
 
 
-class BlockDriver(ForwardDriver):
-    """
-    AIOHTTP 驱动框架
-    """
-
+class BlockDriver(Driver):
     def __init__(self, env: Env, config: Config):
         super().__init__(env, config)
         self.startup_funcs: Set[STARTUP_FUNC] = set()
@@ -29,18 +25,18 @@ class BlockDriver(ForwardDriver):
         self.force_exit: bool = False
 
     @property
-    @overrides(ForwardDriver)
+    @overrides(Driver)
     def type(self) -> str:
         """驱动名称: ``block_driver``"""
         return "block_driver"
 
     @property
-    @overrides(ForwardDriver)
+    @overrides(Driver)
     def logger(self):
         """block driver 使用的 logger"""
         return logger
 
-    @overrides(ForwardDriver)
+    @overrides(Driver)
     def on_startup(self, func: STARTUP_FUNC) -> STARTUP_FUNC:
         """
         :说明:
@@ -54,7 +50,7 @@ class BlockDriver(ForwardDriver):
         self.startup_funcs.add(func)
         return func
 
-    @overrides(ForwardDriver)
+    @overrides(Driver)
     def on_shutdown(self, func: SHUTDOWN_FUNC) -> SHUTDOWN_FUNC:
         """
         :说明:
@@ -68,7 +64,7 @@ class BlockDriver(ForwardDriver):
         self.shutdown_funcs.add(func)
         return func
 
-    @overrides(ForwardDriver)
+    @overrides(Driver)
     def run(self, *args, **kwargs):
         """启动 block driver"""
         super().run(*args, **kwargs)
diff --git a/nonebot/drivers/aiohttp.py b/nonebot/drivers/aiohttp.py
index 031e3b57..f935342c 100644
--- a/nonebot/drivers/aiohttp.py
+++ b/nonebot/drivers/aiohttp.py
@@ -19,7 +19,7 @@ except ImportError:
     ) from None
 
 
-class AiohttpMixin(ForwardMixin):
+class Mixin(ForwardMixin):
     @property
     @overrides(ForwardMixin)
     def type(self) -> str:
@@ -114,4 +114,4 @@ class WebSocket(BaseWebSocket):
         await self.websocket.send_bytes(data)
 
 
-Driver = combine_driver(BlockDriver, AiohttpMixin)
+Driver = combine_driver(BlockDriver, Mixin)
diff --git a/nonebot/drivers/fastapi.py b/nonebot/drivers/fastapi.py
index 0e36bdda..41bd6c71 100644
--- a/nonebot/drivers/fastapi.py
+++ b/nonebot/drivers/fastapi.py
@@ -22,22 +22,10 @@ from starlette.websockets import WebSocket, WebSocketState
 from nonebot.config import Env
 from nonebot.typing import overrides
 from nonebot.utils import escape_tag
-from nonebot.drivers.httpx import HttpxMixin
 from nonebot.config import Config as NoneBotConfig
 from nonebot.drivers import Request as BaseRequest
 from nonebot.drivers import WebSocket as BaseWebSocket
-from nonebot.drivers.websockets import WebSocketsMixin
-from nonebot.drivers import (
-    ReverseDriver,
-    HTTPServerSetup,
-    WebSocketServerSetup,
-    combine_driver,
-)
-
-try:
-    from nonebot.drivers.aiohttp import AiohttpMixin
-except ImportError:
-    AiohttpMixin = None
+from nonebot.drivers import ReverseDriver, HTTPServerSetup, WebSocketServerSetup
 
 
 class Config(BaseSettings):
@@ -317,8 +305,3 @@ class FastAPIWebSocket(BaseWebSocket):
     @overrides(BaseWebSocket)
     async def send_bytes(self, data: bytes) -> None:
         await self.websocket.send({"type": "websocket.send", "bytes": data})
-
-
-FullDriver = combine_driver(Driver, HttpxMixin, WebSocketsMixin)
-if AiohttpMixin:
-    AiohttpDriver = combine_driver(Driver, AiohttpMixin)
diff --git a/nonebot/drivers/httpx.py b/nonebot/drivers/httpx.py
index 1965c439..09234710 100644
--- a/nonebot/drivers/httpx.py
+++ b/nonebot/drivers/httpx.py
@@ -1,5 +1,3 @@
-import httpx
-
 from nonebot.typing import overrides
 from nonebot.drivers._block_driver import BlockDriver
 from nonebot.drivers import (
@@ -11,8 +9,13 @@ from nonebot.drivers import (
     combine_driver,
 )
 
+try:
+    import httpx
+except ImportError:
+    raise ImportError("Please install httpx by using `pip install nonebot2[httpx]`")
 
-class HttpxMixin(ForwardMixin):
+
+class Mixin(ForwardMixin):
     @property
     @overrides(ForwardMixin)
     def type(self) -> str:
@@ -39,7 +42,7 @@ class HttpxMixin(ForwardMixin):
 
     @overrides(ForwardMixin)
     async def websocket(self, setup: Request) -> WebSocket:
-        return await super(HttpxMixin, self).websocket(setup)
+        return await super(Mixin, self).websocket(setup)
 
 
-Driver = combine_driver(BlockDriver, HttpxMixin)
+Driver = combine_driver(BlockDriver, Mixin)
diff --git a/nonebot/drivers/quart.py b/nonebot/drivers/quart.py
index a56d4767..89822ee6 100644
--- a/nonebot/drivers/quart.py
+++ b/nonebot/drivers/quart.py
@@ -17,17 +17,10 @@ from nonebot.config import Env
 from nonebot.log import logger
 from nonebot.typing import overrides
 from nonebot.utils import escape_tag
-from nonebot.drivers.httpx import HttpxMixin
 from nonebot.config import Config as NoneBotConfig
 from nonebot.drivers import Request as BaseRequest
 from nonebot.drivers import WebSocket as BaseWebSocket
-from nonebot.drivers.websockets import WebSocketsMixin
-from nonebot.drivers import (
-    ReverseDriver,
-    HTTPServerSetup,
-    WebSocketServerSetup,
-    combine_driver,
-)
+from nonebot.drivers import ReverseDriver, HTTPServerSetup, WebSocketServerSetup
 
 try:
     from quart import request as _request
@@ -295,6 +288,3 @@ class WebSocket(BaseWebSocket):
     @overrides(BaseWebSocket)
     async def send_bytes(self, data: bytes):
         await self.websocket.send(data)
-
-
-FullDriver = combine_driver(Driver, HttpxMixin, WebSocketsMixin)
diff --git a/nonebot/drivers/websockets.py b/nonebot/drivers/websockets.py
index 7dbd6399..81903698 100644
--- a/nonebot/drivers/websockets.py
+++ b/nonebot/drivers/websockets.py
@@ -1,7 +1,5 @@
 import logging
 
-from websockets.legacy.client import Connect, WebSocketClientProtocol
-
 from nonebot.typing import overrides
 from nonebot.log import LoguruHandler
 from nonebot.drivers import Request, Response
@@ -9,11 +7,18 @@ from nonebot.drivers._block_driver import BlockDriver
 from nonebot.drivers import WebSocket as BaseWebSocket
 from nonebot.drivers import ForwardMixin, combine_driver
 
+try:
+    from websockets.legacy.client import Connect, WebSocketClientProtocol
+except ImportError:
+    raise ImportError(
+        "Please install websockets by using `pip install nonebot2[websockets]`"
+    )
+
 logger = logging.Logger("websockets.client", "INFO")
 logger.addHandler(LoguruHandler())
 
 
-class WebSocketsMixin(ForwardMixin):
+class Mixin(ForwardMixin):
     @property
     @overrides(ForwardMixin)
     def type(self) -> str:
@@ -21,7 +26,7 @@ class WebSocketsMixin(ForwardMixin):
 
     @overrides(ForwardMixin)
     async def request(self, setup: Request) -> Response:
-        return await super(WebSocketsMixin, self).request(setup)
+        return await super(Mixin, self).request(setup)
 
     @overrides(ForwardMixin)
     async def websocket(self, setup: Request) -> "WebSocket":
@@ -75,4 +80,4 @@ class WebSocket(BaseWebSocket):
         await self.websocket.send(data)
 
 
-Driver = combine_driver(BlockDriver, WebSocketsMixin)
+Driver = combine_driver(BlockDriver, Mixin)
diff --git a/nonebot/rule.py b/nonebot/rule.py
index 48c60963..8224e31f 100644
--- a/nonebot/rule.py
+++ b/nonebot/rule.py
@@ -422,7 +422,7 @@ def shell_command(
     命令内容与后续消息间无需空格！
     \:\:\:
     """
-    if not isinstance(parser, ArgumentParser):
+    if parser is not None and not isinstance(parser, ArgumentParser):
         raise TypeError("`parser` must be an instance of nonebot.rule.ArgumentParser")
 
     config = get_driver().config
diff --git a/pyproject.toml b/pyproject.toml
index b6d94cb6..c687ce18 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,13 +28,13 @@ loguru = "^0.5.1"
 pygtrie = "^2.4.1"
 tomlkit = "^0.7.0"
 fastapi = "^0.70.0"
-websockets = ">=9.1"
 typing-extensions = ">=3.10.0,<5.0.0"
 Quart = { version = "^0.16.0", optional = true }
-httpx = { version = ">=0.20.0, <1.0.0", extras = ["http2"] }
+websockets = { version=">=9.1", optional = true }
 pydantic = { version = "~1.8.0", extras = ["dotenv"] }
 uvicorn = { version = "^0.15.0", extras = ["standard"] }
 aiohttp = { version = "^3.7.4", extras = ["speedups"], optional = true }
+httpx = { version = ">=0.20.0, <1.0.0", extras = ["http2"], optional = true }
 
 [tool.poetry.dev-dependencies]
 sphinx = "^4.1.1"
@@ -46,8 +46,10 @@ sphinx-markdown-builder = { git = "https://github.com/nonebot/sphinx-markdown-bu
 
 [tool.poetry.extras]
 quart = ["quart"]
+httpx = ["httpx"]
 aiohttp = ["aiohttp"]
-all = ["quart", "aiohttp"]
+websockets = ["websockets"]
+all = ["quart", "aiohttp", "httpx", "websockets"]
 
 # [[tool.poetry.source]]
 # name = "aliyun"
diff --git a/tests/test_init.py b/tests/test_init.py
index 2018fb75..44411fb4 100644
--- a/tests/test_init.py
+++ b/tests/test_init.py
@@ -15,18 +15,24 @@ os.environ["CONFIG_FROM_ENV"] = '{"test": "test"}'
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "nonebug_init",
-    [{"config_from_init": "init", "driver": "nonebot.drivers.fastapi:FullDriver"}],
+    [
+        {
+            "config_from_init": "init",
+            "driver": "nonebot.drivers.fastapi+nonebot.drivers.httpx+nonebot.drivers.websockets",
+        },
+        {
+            "config_from_init": "init",
+            "driver": "~fastapi+~httpx+~websockets",
+        },
+    ],
     indirect=True,
 )
 async def test_init(nonebug_init):
     from nonebot import get_driver
-    from nonebot.drivers.fastapi import FullDriver
 
     env = get_driver().env
     assert env == "test"
 
-    assert isinstance(get_driver(), FullDriver)
-
     config = get_driver().config
     assert config.config_from_env == {"test": "test"}
     assert config.config_from_init == "init"