diff --git a/src/components/back-top/back-top.vue b/src/components/back-top/back-top.vue
index 482397d7..391ccf28 100644
--- a/src/components/back-top/back-top.vue
+++ b/src/components/back-top/back-top.vue
@@ -67,8 +67,8 @@
                 this.backTop = window.pageYOffset >= this.height;
             },
             back () {
-                let scrollTop = document.documentElement.scrollTop||document.body.scrollTop;
-                scrollTop(window, scrollTop, 0, this.duration);
+                var sTop = document.documentElement.scrollTop||document.body.scrollTop;
+                scrollTop(window, sTop, 0, this.duration);
                 this.$emit('on-click');
             }
         }