diff --git a/core/routers/chat/routes.py b/core/routers/chat/routes.py
index a67547d..fc21a8c 100644
--- a/core/routers/chat/routes.py
+++ b/core/routers/chat/routes.py
@@ -94,7 +94,7 @@ async def get_single_chat_messages(
         db_session: AsyncSession = Depends(get_async_session),
         page: int = Query(default=1, gt=0),
         page_size: int = Query(default=15, gt=0, le=200),
-        last_read_message_id: int = Query(default=0, ge=0),
+        last_read_message_id: int = Query(ge=0)
 ):
     chat: Chat | None = await get_chat(chat_guid, login_user, db_session, is_query_messages=True)
     if not chat:
@@ -103,7 +103,7 @@ async def get_single_chat_messages(
     # 组装查询条件
     conditions = and_(
         Message.chat_id == chat.id,
-        Message.id > last_read_message_id
+        Message.id <= last_read_message_id
     )
 
     # 记录总数查询