<el-table-column header-align="right" align="right" :render-header="renderHeader"><el-table-column prop="week" label="日期"></el-table-column><el-table-column prop="name" label="项目"></el-table-column>
</el-table-column>

js部分

renderHeader(h, {column}) {return h('el-button', {style: 'margin-top: 2px;', // 样式class: '', props: { // 标签自定义属性size: 'medium',type: 'success'},on: {click: this.exportExcel, // 选中事件},}, '导出');},

标签多层嵌套 

在表头添加el-to