1、el-table添加属性row-key
2、el-table-column添加属性reserve-selection为true

<el-table :row-key="getRowKey"><el-table-columntype="selection":reserve-selection="true"@selection-change="selectionChange"></el-table-column>
</el-table>

getRowKey (row) {return row.id
},
selectionChange (val) {this.currentSelection = val
}