diff --git a/packages/form/src/Form.vue b/packages/form/src/Form.vue
index 0f1ed2dc..4bc713a8 100644
--- a/packages/form/src/Form.vue
+++ b/packages/form/src/Form.vue
@@ -86,7 +86,7 @@ export default defineComponent({
     },
 
     size: {
-      type: String,
+      type: String as PropType<'small' | 'default' | 'large'>,
     },
 
     inline: {
diff --git a/packages/form/src/FormDialog.vue b/packages/form/src/FormDialog.vue
index be0a8409..3e152ada 100644
--- a/packages/form/src/FormDialog.vue
+++ b/packages/form/src/FormDialog.vue
@@ -78,7 +78,7 @@ export default defineComponent({
 
     labelWidth: [Number, String],
 
-    size: String as PropType<'mini' | 'small' | 'medium'>,
+    size: String as PropType<'small' | 'default' | 'large'>,
 
     confirmText: {
       type: String,