SOURCE

new Vue({
    data() {
        return {
            aaa: 3
        };
    },
    methods: {
        callback(key) {
            console.log(key);
        },
    },
}).$mount('#app')

<div id="app">
    asdf 
	<div>
    <a-tabs v-model="aaa" @change="callback">
      <a-tab-pane key="1" tab="Tab 1">
        Content of Tab Pane 1
      </a-tab-pane>
      <a-tab-pane key="2" tab="Tab 2" force-render>
        Content of Tab Pane 2
      </a-tab-pane>
      <a-tab-pane :key="3" tab="Tab 3">
        Content of Tab Pane 3
      </a-tab-pane>
    </a-tabs>
  </div>
</div>