diff --git a/flocks/server/routes/workflow.py b/flocks/server/routes/workflow.py
index 77ea94825..97a78f8fe 100644
--- a/flocks/server/routes/workflow.py
+++ b/flocks/server/routes/workflow.py
@@ -1436,7 +1436,7 @@ class SyslogConfigRequest(BaseModel):
     enabled: bool = False
     protocol: str = "udp"
     host: str = "0.0.0.0"
-    port: int = 5140
+    port: int = Field(5140, ge=1, le=65535, description="Listener port (1-65535)")
     msg_format: str = Field("auto", alias="format")
     input_key: str = Field("syslog_message", alias="inputKey")
 
diff --git a/webui/src/locales/en-US/workflow.json b/webui/src/locales/en-US/workflow.json
index 303565d56..5f11d0227 100644
--- a/webui/src/locales/en-US/workflow.json
+++ b/webui/src/locales/en-US/workflow.json
@@ -214,6 +214,7 @@
       "syslogFormat": "Parse format",
       "syslogInputKey": "Inputs key",
       "syslogHint": "When enabled, Flocks listens for syslog on the given address/port and passes parsed payloads to workflow inputs (default key: syslog_message).",
+      "syslogPortError": "Invalid port: must be an integer between 1 and 65535",
       "syslogActive": "Listening",
       "historySection": "Execution History",
       "noHistory": "No execution records",
diff --git a/webui/src/locales/zh-CN/workflow.json b/webui/src/locales/zh-CN/workflow.json
index 2524d9925..a87304085 100644
--- a/webui/src/locales/zh-CN/workflow.json
+++ b/webui/src/locales/zh-CN/workflow.json
@@ -214,6 +214,7 @@
       "syslogFormat": "解析格式",
       "syslogInputKey": "Inputs 键名",
       "syslogHint": "开启后 Flocks 在指定地址/端口接收 syslog，解析结果写入工作流 inputs（默认键名 syslog_message）。",
+      "syslogPortError": "端口范围无效，请输入 1 ~ 65535 之间的整数",
       "syslogActive": "监听中",
       "historySection": "执行历史",
       "noHistory": "暂无执行记录",
diff --git a/webui/src/pages/WorkflowDetail/tabs/IntegrationTab.tsx b/webui/src/pages/WorkflowDetail/tabs/IntegrationTab.tsx
index 71e8666a7..b98bd9e18 100644
--- a/webui/src/pages/WorkflowDetail/tabs/IntegrationTab.tsx
+++ b/webui/src/pages/WorkflowDetail/tabs/IntegrationTab.tsx
@@ -322,6 +322,7 @@ function SyslogSection({ workflowId }: { workflowId: string }) {
   // falsely showing the listener as active.
   const [listener, setListener] = useState<SyslogListenerStatus | null>(null);
   const [saveError, setSaveError] = useState<string>('');
+  const [portError, setPortError] = useState<string>('');
 
   const refreshStatus = useCallback(async () => {
     try {
@@ -387,7 +388,32 @@ function SyslogSection({ workflowId }: { workflowId: string }) {
     return () => window.clearInterval(handle);
   }, [isBinding, refreshStatus]);
 
+  const validatePort = (value: string): boolean => {
+    const trimmed = value.trim();
+    if (!/^\d+$/.test(trimmed)) {
+      setPortError(t('detail.run.syslogPortError'));
+      return false;
+    }
+    const num = Number.parseInt(trimmed, 10);
+    if (num < 1 || num > 65535) {
+      setPortError(t('detail.run.syslogPortError'));
+      return false;
+    }
+    setPortError('');
+    return true;
+  };
+
+  const handlePortChange = (value: string) => {
+    setPort(value);
+    if (value !== '') {
+      validatePort(value);
+    } else {
+      setPortError('');
+    }
+  };
+
   const handleSave = async () => {
+    if (!validatePort(port)) return;
     setSaving(true);
     setSaved(false);
     setSaveError('');
@@ -466,7 +492,19 @@ function SyslogSection({ workflowId }: { workflowId: string }) {
               </select>
             </div>
             {inputField(t('detail.run.syslogHost'), host, setHost, '0.0.0.0')}
-            {inputField(t('detail.run.syslogPort'), port, setPort, '5140')}
+            <div>
+              <label className="block text-xs text-gray-500 mb-1">{t('detail.run.syslogPort')}</label>
+              <input
+                type="text"
+                value={port}
+                onChange={e => handlePortChange(e.target.value)}
+                placeholder="5140"
+                className={`w-full text-xs border rounded-lg px-3 py-1.5 focus:outline-none focus:ring-1 ${portError ? 'border-red-400 focus:ring-red-500' : 'border-gray-200 focus:ring-red-500'}`}
+              />
+              {portError && (
+                <p className="text-xs text-red-500 mt-1">{portError}</p>
+              )}
+            </div>
             <div>
               <label className="block text-xs text-gray-500 mb-1">{t('detail.run.syslogFormat')}</label>
               <select
@@ -484,7 +522,7 @@ function SyslogSection({ workflowId }: { workflowId: string }) {
           <button
             type="button"
             onClick={handleSave}
-            disabled={saving}
+            disabled={saving || !!portError}
             className="w-full flex items-center justify-center gap-2 py-2 border border-gray-200 text-gray-600 text-xs font-medium rounded-lg hover:bg-gray-50 disabled:opacity-60 transition-colors"
           >
             {saving ? (
diff --git a/webui/src/utils/error.ts b/webui/src/utils/error.ts
index f47d53bc6..ac918d99a 100644
--- a/webui/src/utils/error.ts
+++ b/webui/src/utils/error.ts
@@ -7,13 +7,24 @@
  * Standard FastAPI/Starlette errors use:
  *   { "detail": "..." }
  *
+ * Pydantic validation errors (HTTP 422) use a list shape:
+ *   { "detail": [{ "loc": [...], "msg": "...", "type": "..." }, ...] }
+ *
  * This helper checks all known fields before falling back to err.message.
  */
 export function extractErrorMessage(err: unknown, fallback = '操作失败'): string {
   if (!err) return fallback;
   const e = err as any;
+  const detail = e?.response?.data?.detail;
+  if (Array.isArray(detail)) {
+    const msgs = detail
+      .map((d: any) => (typeof d === 'string' ? d : d?.msg || JSON.stringify(d)))
+      .filter(Boolean);
+    if (msgs.length > 0) return msgs.join('; ');
+  } else if (typeof detail === 'string' && detail) {
+    return detail;
+  }
   return (
-    e?.response?.data?.detail ||
     e?.response?.data?.message ||
     e?.message ||
     fallback