diff --git a/app/Services/AiChatService.php b/app/Services/AiChatService.php
index d457732..87e3984 100644
--- a/app/Services/AiChatService.php
+++ b/app/Services/AiChatService.php
@@ -26,8 +26,10 @@ class AiChatService
 {
     /**
      * 每个用户保留的最大对话轮数
+     *
+     * 设置较小值可减少 token 输入量，加快本地 Ollama CPU 推理速度。
      */
-    private const MAX_CONTEXT_ROUNDS = 10;
+    private const MAX_CONTEXT_ROUNDS = 4;
 
     /**
      * AI 请求超时时间（秒）