this.$nextTick(() => {
	  // 加载loading
      this.loading = this.$loading({
        lock: true,
        text: 'Loading',
        spinner: 'el-icon-loading',
        background: 'rgba(0, 0, 0, 0.7)',
        target: document.querySelector('.dialog-box-distinguish') // 在指定得到元素上显示loading，要设置下相对定位
      });
})
// 关闭loading
	this.loading.close();
<style lang="scss" scoped>
	.dialog-box-distinguish {
		position: relative;
	}
</style>