diff --git a/frontend/src/mock/index.ts b/frontend/src/mock/index.ts
index e6f3f1a..487a129 100644
--- a/frontend/src/mock/index.ts
+++ b/frontend/src/mock/index.ts
@@ -25,6 +25,7 @@ const routes: Route[] = [
   { m: 'delete', re: /^\/strategy\/instances\/[^/]+$/, build: () => ({ ok: true }) },
   // strategy code files（在线编辑）
   { m: 'get', re: /^\/strategy\/files$/, build: () => D.strategyFilesMock },
+  { m: 'post', re: /^\/strategy\/file\/[^/]+\/check$/, build: () => ({ ok: true }) },
   { m: 'post', re: /^\/strategy\/file\/[^/]+$/, build: () => ({ ok: true }) },
   // strategy configs（CRUD）
   { m: 'get', re: /^\/strategy\/configs$/, build: () => D.strategyConfigsMock },
diff --git a/frontend/src/views/strategy/Code.vue b/frontend/src/views/strategy/Code.vue
index 5a92476..80c50a9 100644
--- a/frontend/src/views/strategy/Code.vue
+++ b/frontend/src/views/strategy/Code.vue
@@ -23,6 +23,7 @@ const dirty = ref(false)
 const saving = ref(false)
 const checking = ref(false)
 const syntaxOk = ref<boolean | null>(null)
+const syntaxError = ref<string | null>(null)
 
 const active = computed(() => files.value.find((f) => f.name === activeName.value))
 
@@ -60,6 +61,7 @@ async function select(f: StrategyFile): Promise<void> {
   activeName.value = f.name
   dirty.value = false
   syntaxOk.value = null
+  syntaxError.value = null
   loadingCode.value = true
   try {
     const { data } = await apiClient.get<{ code: string }>(`/strategy/file/${f.name}`)
@@ -78,14 +80,29 @@ watch(code, () => {
   if (echoGrace) return
   dirty.value = true
   syntaxOk.value = null
+  syntaxError.value = null
 })
 
 async function onCheck(): Promise<void> {
+  if (!active.value) return
   checking.value = true
-  await new Promise((r) => setTimeout(r, 600)) // 模拟 py_compile
-  syntaxOk.value = true
-  checking.value = false
-  ElMessage.success('语法检查通过')
+  syntaxError.value = null
+  try {
+    const { data } = await apiClient.post<{ ok: boolean; error?: string; line?: number | null }>(
+      `/strategy/file/${activeName.value}/check`, { code: code.value })
+    if (data.ok) {
+      syntaxOk.value = true
+      ElMessage.success('语法检查通过')
+    } else {
+      syntaxOk.value = false
+      syntaxError.value = data.line != null ? `第 ${data.line} 行：${data.error ?? '语法错误'}` : (data.error ?? '语法错误')
+      ElMessage.error(syntaxError.value)
+    }
+  } catch (e) {
+    ElMessage.error(e instanceof Error ? e.message : '语法检查请求失败')
+  } finally {
+    checking.value = false
+  }
 }
 
 async function onSave(): Promise<void> {
@@ -162,6 +179,7 @@ function runBacktest(): void {
             <span class="path mono">{{ active?.dir }}{{ activeName }}</span>
             <span v-if="dirty" class="tag tag-dirty">未保存</span>
             <span v-if="syntaxOk" class="tag tag-ok mono">✓ 语法正确</span>
+            <span v-else-if="syntaxError" class="tag tag-err mono" :title="syntaxError">✗ {{ syntaxError }}</span>
           </div>
           <div class="bar-right">
             <span class="modified mono">{{ active?.modified }}</span>
@@ -298,6 +316,7 @@ function runBacktest(): void {
   font-family: var(--mono);
 }
 .tag-dirty { color: var(--lamp-warn); background: var(--amber-soft); border: 1px solid rgba(255, 176, 0, 0.3); }
+.tag-err { color: var(--lamp-err, #ff5470); background: rgba(255, 84, 112, 0.1); border: 1px solid rgba(255, 84, 112, 0.3); max-width: 46ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .tag-ok { color: var(--lamp-ok); background: rgba(46, 230, 138, 0.1); border: 1px solid rgba(46, 230, 138, 0.3); }
 
 .monaco-wrap {
diff --git a/sanguo_api/routes_strategy.py b/sanguo_api/routes_strategy.py
index 21175fa..3846f47 100644
--- a/sanguo_api/routes_strategy.py
+++ b/sanguo_api/routes_strategy.py
@@ -53,6 +53,23 @@ def post_file(name: str, req: FileWriteRequest):
     return {"ok": True}
 
 
+@router.post("/strategy/file/{name}/check")
+def check_file(name: str, req: FileWriteRequest):
+    """语法检查（不落盘）：编辑器「语法检查」按钮真接线。
+
+    原前端按钮是原型期假实现（sleep 600ms 恒报通过，2026-08-15 用户实况
+    删括号仍报成功）。compile() 不执行代码，只做语法编译；SyntaxError
+    返回行号+消息供编辑器定位。
+    """
+    try:
+        compile(req.code, name, "exec")
+    except SyntaxError as e:
+        return {"ok": False, "error": str(e.msg or e), "line": e.lineno}
+    except ValueError as e:  # null bytes 等 compile 级错误
+        return {"ok": False, "error": str(e), "line": None}
+    return {"ok": True}
+
+
 @router.get("/strategy/instances")
 def get_instances():
     return instance_store.list_instances()
diff --git a/tests/api/test_routes_strategy.py b/tests/api/test_routes_strategy.py
index 4eb1508..e123208 100644
--- a/tests/api/test_routes_strategy.py
+++ b/tests/api/test_routes_strategy.py
@@ -67,3 +67,33 @@ def test_file_read_returns_code(monkeypatch, tmp_path):
     assert isinstance(body["code"], str) and body["code"]  # 编辑器空白 bug 的回归测试
     assert body["name"] == name
     assert c.get("/api/v1/strategy/file/__no_such__.py").status_code == 404
+
+
+# ===== 语法检查端点(编辑器「语法检查」按钮真接线)=====
+
+def test_check_syntax_ok(monkeypatch, tmp_path):
+    c = _client(monkeypatch, tmp_path)
+    r = c.post("/api/v1/strategy/file/foo.py/check",
+               json={"code": "x = [1, 2, 3]\nprint(x)\n"})
+    assert r.status_code == 200
+    assert r.json() == {"ok": True}
+
+
+def test_check_syntax_catches_missing_bracket(monkeypatch, tmp_path):
+    """删掉一个中括号必须报错并给行号(2026-08-15 用户实况:删括号仍报通过)。"""
+    c = _client(monkeypatch, tmp_path)
+    r = c.post("/api/v1/strategy/file/foo.py/check",
+               json={"code": "x = [1, 2, 3\nprint(x)\n"})
+    assert r.status_code == 200
+    body = r.json()
+    assert body["ok"] is False
+    assert body["line"] is not None and body["line"] >= 1
+    assert body["error"]
+
+
+def test_check_syntax_empty_code_ok(monkeypatch, tmp_path):
+    """空代码/纯注释可编译 → ok(编辑器允许半成品里写注释)。"""
+    c = _client(monkeypatch, tmp_path)
+    r = c.post("/api/v1/strategy/file/foo.py/check", json={"code": "# 只有注释\n"})
+    assert r.status_code == 200
+    assert r.json()["ok"] is True