diff --git a/packages/ui/src/components/CodeBlock.tsx b/packages/ui/src/components/CodeBlock.tsx
index 1f23a17..68eb014 100644
--- a/packages/ui/src/components/CodeBlock.tsx
+++ b/packages/ui/src/components/CodeBlock.tsx
@@ -4,7 +4,7 @@
  * 代码块组件，支持语法高亮和一键复制
  */
 
-import { useState, useEffect } from 'react';
+import { useState, useEffect, useRef } from 'react';
 import { Copy, Check } from 'lucide-react';
 import { codeToHtml } from 'shiki';
 import { cn } from '../utils/cn';
@@ -18,37 +18,42 @@ interface CodeBlockProps {
 export function CodeBlock({ code, language = 'text', className }: CodeBlockProps) {
   const [copied, setCopied] = useState(false);
   const [highlightedHtml, setHighlightedHtml] = useState<string>('');
-  const [isLoading, setIsLoading] = useState(true);
+  // 使用 ref 跟踪上一次高亮的代码，避免不必要的重新高亮
+  const lastHighlightedCode = useRef<string>('');
+  const highlightTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
 
-  // 语法高亮
+  // 语法高亮 - 使用防抖避免频繁高亮导致闪烁
   useEffect(() => {
-    let cancelled = false;
+    // 清除之前的定时器
+    if (highlightTimer.current) {
+      clearTimeout(highlightTimer.current);
+    }
 
-    async function highlight() {
+    // 如果代码没变，不需要重新高亮
+    if (code === lastHighlightedCode.current && highlightedHtml) {
+      return;
+    }
+
+    // 使用防抖：等待 150ms 后再进行高亮（流式输出时减少高亮次数）
+    highlightTimer.current = setTimeout(async () => {
       try {
         const html = await codeToHtml(code, {
           lang: language,
           theme: 'github-dark',
         });
-        if (!cancelled) {
-          setHighlightedHtml(html);
-        }
+        lastHighlightedCode.current = code;
+        setHighlightedHtml(html);
       } catch {
         // 如果语言不支持，回退到纯文本
-        if (!cancelled) {
-          setHighlightedHtml(`<pre><code>${escapeHtml(code)}</code></pre>`);
-        }
-      } finally {
-        if (!cancelled) {
-          setIsLoading(false);
-        }
+        lastHighlightedCode.current = code;
+        setHighlightedHtml(`<pre><code>${escapeHtml(code)}</code></pre>`);
       }
-    }
-
-    highlight();
+    }, 150);
 
     return () => {
-      cancelled = true;
+      if (highlightTimer.current) {
+        clearTimeout(highlightTimer.current);
+      }
     };
   }, [code, language]);
 
@@ -82,17 +87,17 @@ export function CodeBlock({ code, language = 'text', className }: CodeBlockProps
         </button>
       </div>
 
-      {/* 代码内容 */}
+      {/* 代码内容 - 始终显示高亮后的内容，未高亮时显示纯文本 */}
       <div className="overflow-x-auto">
-        {isLoading ? (
-          <pre className="p-4 bg-code text-fg-secondary text-sm font-mono">
-            <code>{code}</code>
-          </pre>
-        ) : (
+        {highlightedHtml ? (
           <div
             className="shiki-wrapper text-sm [&>pre]:p-4 [&>pre]:m-0 [&>pre]:bg-code"
             dangerouslySetInnerHTML={{ __html: highlightedHtml }}
           />
+        ) : (
+          <pre className="p-4 bg-code text-fg-secondary text-sm font-mono">
+            <code>{code}</code>
+          </pre>
         )}
       </div>
     </div>