diff --git a/src/parse.py b/src/parse.py
index a418715..9203132 100644
--- a/src/parse.py
+++ b/src/parse.py
@@ -222,7 +222,7 @@ class PDFParser:
                     {"role": "system", "content": system_prompt},
                     {"role": "user", "content": user_prompt}
                 ],
-                "max_tokens": 100,  # 需要返回更复杂的JSON格式
+                "max_tokens": 1000,  # 增加token数量以确保完整JSON响应
                 "temperature": 0.1  # 降低随机性
             }
             
@@ -236,7 +236,13 @@ class PDFParser:
             
             if response.status_code == 200:
                 result = response.json()
-                ai_response = result['choices'][0]['message']['content'].strip()
+                # 检查AI响应内容是否为None
+                content = result.get('choices', [{}])[0].get('message', {}).get('content')
+                if content is None:
+                    logging.error(f"AI API返回的content为None，可能是服务器问题")
+                    return {'is_medical': False, 'task_type': 'none', 'medical_confidence': 0.0, 'task_confidence': 0.0}
+                
+                ai_response = content.strip()
                 
                 try:
                     # 解析JSON响应