npm install --save vue-clipboard2

import VueClipboard from 'vue-clipboard2';
Vue.use(VueClipboard);

 <button class="but"
            type="primary"
            size="small"
            v-clipboard:copy="key"
            v-clipboard:success="onCopy"
            v-clipboard:error="onError">复制</button>

   onCopy(){
      let that=this;
      that.$copyText(this.linkValue).then(function (e) {
          that.$message.success('链接复制成功');
        }, function (e) {
          that.$message.error('链接复制失败');
      })
    },