diff --git a/src/services/openaiToClaude.js b/src/services/openaiToClaude.js
index ccb133ce..ded54774 100644
--- a/src/services/openaiToClaude.js
+++ b/src/services/openaiToClaude.js
@@ -33,8 +33,16 @@ class OpenAIToClaudeConverter {
 
     // 处理系统消息
     const systemMessage = this._extractSystemMessage(openaiRequest.messages);
+    
+    // Claude Code 必需的系统消息
+    const claudeCodeSystemMessage = 'You are Claude Code, Anthropic\'s official CLI for Claude.';
+    
     if (systemMessage) {
-      claudeRequest.system = systemMessage;
+      // 如果已有系统消息，合并它们
+      claudeRequest.system = `${claudeCodeSystemMessage}\n\n${systemMessage}`;
+    } else {
+      // 如果没有系统消息，只使用 Claude Code 消息
+      claudeRequest.system = claudeCodeSystemMessage;
     }
 
     // 处理停止序列