diff --git a/frontend/src/components/chat/MessageInput.tsx b/frontend/src/components/chat/MessageInput.tsx
index c4ab8f6e..fb45acae 100644
--- a/frontend/src/components/chat/MessageInput.tsx
+++ b/frontend/src/components/chat/MessageInput.tsx
@@ -122,12 +122,13 @@ const MessageInput: React.FC<MessageInputProps> = ({
           <Space>
             {/* @知识库按钮 */}
             {knowledgeBases.length > 0 && (
-              <Dropdown
-                menu={{ items: knowledgeBaseMenuItems }}
-                placement="topLeft"
-                disabled={loading}
-              >
-                <Tooltip title="@知识库 - 基于知识库内容回答">
+              <Tooltip title="@知识库 - 基于知识库内容回答">
+                <Dropdown
+                  menu={{ items: knowledgeBaseMenuItems }}
+                  placement="topLeft"
+                  trigger={['click']}
+                  disabled={loading}
+                >
                   <Button
                     icon={<FileTextOutlined />}
                     type="text"
@@ -135,8 +136,8 @@ const MessageInput: React.FC<MessageInputProps> = ({
                   >
                     @知识库
                   </Button>
-                </Tooltip>
-              </Dropdown>
+                </Dropdown>
+              </Tooltip>
             )}
 
             {/* 上传附件按钮（预留） */}