diff --git a/packages/designer/src/builtin-simulator/bem-tools/borders.less b/packages/designer/src/builtin-simulator/bem-tools/borders.less
index 511bae9c2..b602193b5 100644
--- a/packages/designer/src/builtin-simulator/bem-tools/borders.less
+++ b/packages/designer/src/builtin-simulator/bem-tools/borders.less
@@ -25,6 +25,9 @@
     align-items: stretch;
     justify-content: flex-end;
     pointer-events: all;
+    > * {
+      flex-shrink: 0;
+    }
   }
 
   &-action {