diff --git a/packages/tabs/index.vue b/packages/tabs/index.vue
index 89c351b5f..1e1391ab6 100644
--- a/packages/tabs/index.vue
+++ b/packages/tabs/index.vue
@@ -256,7 +256,7 @@ export default create({
         }
 
         const tab = this.$refs.tabs[this.curActive];
-        const width = this.lineWidth || tab.offsetWidth;
+        const width = this.lineWidth || (tab.offsetWidth / 2);
         const left = tab.offsetLeft + (tab.offsetWidth - width) / 2;
 
         this.lineStyle = {
diff --git a/packages/vant-css/src/tab.css b/packages/vant-css/src/tab.css
index 593a368ed..120737872 100644
--- a/packages/vant-css/src/tab.css
+++ b/packages/vant-css/src/tab.css
@@ -86,6 +86,7 @@ $van-tabs-card-height: 30px;
     bottom: 15px;
     height: 2px;
     position: absolute;
+    border-radius: 2px 0;
     background-color: $red;
   }