diff --git a/packages/form/spec/form.spec.ts b/packages/form/spec/form.spec.ts
index edec1b00d3..8ee4aaf698 100644
--- a/packages/form/spec/form.spec.ts
+++ b/packages/form/spec/form.spec.ts
@@ -135,6 +135,18 @@ describe('form: component', () => {
         );
       });
     });
+    describe('#size', () => {
+      it('with small', () => {
+        context.button = { render: { size: 'small' } };
+        fixture.detectChanges();
+        page.checkCount('.ant-btn-sm', 2);
+      });
+      it('with large', () => {
+        context.button = { render: { size: 'large' } };
+        fixture.detectChanges();
+        page.checkCount('.ant-btn-lg', 2);
+      });
+    });
   });
 
   describe('properites', () => {
diff --git a/packages/form/src/sf.component.html b/packages/form/src/sf.component.html
index 2d78d80506..1e035261e3 100644
--- a/packages/form/src/sf.component.html
+++ b/packages/form/src/sf.component.html
@@ -10,8 +10,12 @@
               [nzLg]="_btn.render.grid.lg" [nzXl]="_btn.render.grid.xl" [nzXXl]="_btn.render.grid.xxl">
         <div class="ant-form-item-control">
           <ng-container *ngIf="button; else con">
-            <button type="submit" nz-button [nzType]="_btn.submit_type" [disabled]="liveValidate && !valid">{{_btn.submit}}</button>
-            <button *ngIf="_btn.reset" (click)="reset(true)" type="button" nz-button [nzType]="_btn.reset_type">{{_btn.reset}}</button>
+            <button type="submit" nz-button [nzType]="_btn.submit_type" [nzSize]="_btn.render.size"
+              [disabled]="liveValidate && !valid">{{_btn.submit}}</button>
+            <button *ngIf="_btn.reset" type="button" nz-button
+              [nzType]="_btn.reset_type" [nzSize]="_btn.render.size" (click)="reset(true)">
+              {{_btn.reset}}
+            </button>
           </ng-container>
         </div>
       </div>
diff --git a/packages/form/src/sf.component.ts b/packages/form/src/sf.component.ts
index e3ce5645b8..4c4d7197c2 100644
--- a/packages/form/src/sf.component.ts
+++ b/packages/form/src/sf.component.ts
@@ -328,7 +328,7 @@ export class SFComponent implements OnInit, OnChanges, OnDestroy {
 
   private coverButtonProperty() {
     this._btn = Object.assign(
-      { render: {} },
+      <SFButton>{ render: { size: 'default' } },
       this.locale,
       this.options.button,
       this.button,