diff --git a/lib/wxpay.js b/lib/wxpay.js
index 969ac13..ce094ed 100644
--- a/lib/wxpay.js
+++ b/lib/wxpay.js
@@ -72,7 +72,13 @@ WXPay.mix('createUnifiedOrder', function(opts, fn){
 			passphrase: this.options.mch_id
 		}
 	}, function(err, response, body){
-		util.parseXML(body, fn);
+		util.parseXML(body, function(err, result){
+		      if (err) {
+			return fn(err)
+		      }
+		      result.nonce_str = opts.nonce_str
+		      fn(null, result)
+		    });
 	});
 });
 
@@ -81,6 +87,10 @@ WXPay.mix('getBrandWCPayRequestParams', function(order, fn){
 	order.trade_type = "JSAPI";
 	var _this = this;
 	this.createUnifiedOrder(order, function(err, data){
+		if (data.return_code === 'FAIL') {
+      		  fn(data)
+     		  return
+    		}
 		var reqparam = {
 			appId: _this.options.appid,
 			timeStamp: Math.floor(Date.now()/1000)+"",