diff --git a/packages/dialog/src/component.vue b/packages/dialog/src/component.vue
index 3f9035f37..6550f5188 100644
--- a/packages/dialog/src/component.vue
+++ b/packages/dialog/src/component.vue
@@ -110,7 +110,7 @@
         return `el-dialog--${ this.size }`;
       },
       style() {
-        return this.size === 'full' ? {} : { 'margin-bottom': '50px', 'top': this.top };
+        return this.size === 'full' ? {} : { 'top': this.top };
       }
     },
 
diff --git a/packages/theme-default/src/dialog.css b/packages/theme-default/src/dialog.css
index 015841fba..6f7a8495d 100755
--- a/packages/theme-default/src/dialog.css
+++ b/packages/theme-default/src/dialog.css
@@ -12,6 +12,7 @@
     border-radius: var(--border-radius-small);
     box-shadow: var(--dialog-box-shadow);
     box-sizing: border-box;
+    margin-bottom: 50px;
 
     @modifier tiny {
       width: var(--dialog-tiny-width);
@@ -28,6 +29,7 @@
     @modifier full {
       width: 100%;
       top: 0;
+      margin-bottom: 0;
       height: 100%;
       overflow: auto;
     }