element通过业务按钮点击导入，调用el-upload的导入方法

this.$refs["upload"].$refs["upload-inner"].handleClick();

<el-button @click="getImport>导入</el-button>

<el-upload

ref="upload"

   **********

>

</el-upload>

methods:{

         getImport(){

               this.$refs["upload"].$refs["upload-inner"].handleClick();

          }

}