diff --git a/packages/vant-css/src/goods-action.css b/packages/vant-css/src/goods-action.css
index ce63f0009..826b355d6 100644
--- a/packages/vant-css/src/goods-action.css
+++ b/packages/vant-css/src/goods-action.css
@@ -9,6 +9,11 @@
 
   &__big-btn {
     flex: 1;
+    padding: 0;
+
+    @media(max-width: 321px) {
+      font-size: 15px;
+    }
   }
 
   &__mini-btn {