diff --git a/packages/taro-alipay/src/runtime.ts b/packages/taro-alipay/src/runtime.ts
index d8cccb2f4fb4..a106709f3fba 100644
--- a/packages/taro-alipay/src/runtime.ts
+++ b/packages/taro-alipay/src/runtime.ts
@@ -1,5 +1,15 @@
 import { mergeReconciler, mergeInternalComponents } from '@tarojs/shared'
 import { hostConfig, components } from './runtime-utils'
 
+// 支付宝真机只有 navigator.swuserAgent
+const { userAgent } = navigator
+Object.defineProperty(navigator, 'userAgent', {
+  configurable: true,
+  enumerable: true,
+  get () {
+    return userAgent || (navigator as any).swuserAgent || ''
+  }
+})
+
 mergeReconciler(hostConfig)
 mergeInternalComponents(components)