diff --git a/packages/nonebot-adapter-cqhttp/nonebot/adapters/cqhttp/message.py b/packages/nonebot-adapter-cqhttp/nonebot/adapters/cqhttp/message.py
index 79b016bd..42cbc8ac 100644
--- a/packages/nonebot-adapter-cqhttp/nonebot/adapters/cqhttp/message.py
+++ b/packages/nonebot-adapter-cqhttp/nonebot/adapters/cqhttp/message.py
@@ -89,7 +89,7 @@ class MessageSegment(BaseMessageSegment["Message"]):
               proxy: bool = True,
               timeout: Optional[int] = None) -> "MessageSegment":
         if isinstance(file, BytesIO):
-            file = file.read()
+            file = file.getvalue()
         if isinstance(file, bytes):
             file = f"base64://{b64encode(file).decode()}"
         elif isinstance(file, Path):