diff --git a/agent/mem0_middleware.py b/agent/mem0_middleware.py
index 4cf8d10..f84da01 100644
--- a/agent/mem0_middleware.py
+++ b/agent/mem0_middleware.py
@@ -356,7 +356,18 @@ class Mem0Middleware(AgentMiddleware):
         # 获取当前系统提示词
         current_system_prompt = ""
         if request.system_message:
-            current_system_prompt = request.system_message.content if hasattr(request.system_message, "content") else str(request.system_message)
+            content = request.system_message.content if hasattr(request.system_message, "content") else str(request.system_message)
+            # content 可能是 list 或 str，确保转换为 str
+            if isinstance(content, list):
+                current_system_prompt = "\n".join(str(item) for item in content)
+            else:
+                current_system_prompt = str(content) if content else ""
+
+        # 确保 memory_prompt 也是字符串
+        if isinstance(memory_prompt, list):
+            memory_prompt = "\n".join(str(item) for item in memory_prompt)
+        else:
+            memory_prompt = str(memory_prompt) if memory_prompt else ""
 
         # 修改系统提示词
         new_system_prompt = current_system_prompt + memory_prompt
@@ -384,7 +395,18 @@ class Mem0Middleware(AgentMiddleware):
         # 获取当前系统提示词
         current_system_prompt = ""
         if request.system_message:
-            current_system_prompt = request.system_message.content if hasattr(request.system_message, "content") else str(request.system_message)
+            content = request.system_message.content if hasattr(request.system_message, "content") else str(request.system_message)
+            # content 可能是 list 或 str，确保转换为 str
+            if isinstance(content, list):
+                current_system_prompt = "\n".join(str(item) for item in content)
+            else:
+                current_system_prompt = str(content) if content else ""
+
+        # 确保 memory_prompt 也是字符串
+        if isinstance(memory_prompt, list):
+            memory_prompt = "\n".join(str(item) for item in memory_prompt)
+        else:
+            memory_prompt = str(memory_prompt) if memory_prompt else ""
 
         # 修改系统提示词
         new_system_prompt = current_system_prompt + memory_prompt