diff --git a/group_video_man/bot_video_man.py b/group_video_man/bot_video_man.py
index 690043e..e13be3d 100644
--- a/group_video_man/bot_video_man.py
+++ b/group_video_man/bot_video_man.py
@@ -46,6 +46,14 @@ class BotVideoMan:
             return
 
     def download_video(self, api_url, save_dir):
+        # 确保 save_dir 是一个目录
+        if os.path.isfile(save_dir):
+            print(f"错误: {save_dir} 是一个文件，不能作为目录使用。")
+            return None
+
+        os.makedirs(save_dir, exist_ok=True)
+        save_path = os.path.join(save_dir, "video.mp4")
+
         response = requests.get(api_url)
         if response.status_code == 200:
             data = response.json()
@@ -53,8 +61,6 @@ class BotVideoMan:
             if video_url:
                 video_response = requests.get(video_url, stream=True)
                 if video_response.status_code == 200:
-                    os.makedirs(save_dir, exist_ok=True)
-                    save_path = os.path.join(save_dir, "video.mp4")
                     with open(save_path, "wb") as file:
                         for chunk in video_response.iter_content(chunk_size=1024):
                             file.write(chunk)