diff --git a/webapp/sdkwarpper/UnifiedWeiXin.php b/webapp/sdkwarpper/UnifiedWeiXin.php
index aed9728..e4ccfa0 100644
--- a/webapp/sdkwarpper/UnifiedWeiXin.php
+++ b/webapp/sdkwarpper/UnifiedWeiXin.php
@@ -109,11 +109,29 @@ class UnifiedWeiXin extends BaseSdk {
                 'errcode' => 0,
                 'errmsg' => '',
                 'cp_orderid' => $cp_orderid,
-                'prepayid' => '' . $xml->prepay_id
+                'prepayid' => $this->genJSApiData(
+                    $this->conf_appid,
+                    $cp_orderid,
+                    $xml->prepay_id)
             ));
         }
     }
 
+    private function genJSApiData($appid, $cp_orderid, $prepay_id)
+    {
+        $data = array(
+            'appId' => $appid,
+            'timeStamp' => time(),
+            'nonceStr' => md5($cp_orderid . uniqid()),
+            'package' => 'prepay_id=' . $prepay_id,
+        );
+        $data['paySign'] = phpcommon\wxPaySign($data,
+                                               $this->conf_pay_secret_key
+        );
+        $data['signType'] = 'MD5';
+        return json_encode($data);
+    }
+
     public function payNotify()
     {
         $raw_data = file_get_contents('php://input');