<el-table :data="tableData" style="width: 100%" :border="true">
 <el-table-column prop="date" label="日期" min-width="20%" align="center">
 </el-table-column>
 <el-table-column prop="name" label="姓名" min-width="60%" align="center">
 </el-table-column>
 <el-table-column prop="address" label="地址" align="center">
 </el-table-column>
</el-table>

<el-table-column :render-header="renderHeader" prop="name" label="姓名" min-width="60%" align="center" >
</el-table-column>

methods: {
 renderHeader (createElement) {
  let self = this
  return createElement('div', {
  domProps: {
   innerHTML: `
    <span class="span">姓名</span>
    <input type="text" class="input">
    `
  },
  style: {
   padding: '0',
   lineHeight: '1',
   marginTop: '5px',
   width: '100%'
  },
  on: {
   '!click': function (e) {
   let span = document.getElementsByClassName('span')[0]
   let input = document.getElementsByClassName('input')[0]
   span.style.display = 'none'
   input.style.display = 'inline-block'
   input.focus()
   event.stopPropagation()
   }
  }
  })
 }
 },

.span {
  display: inline-block;
}
.input {
  display: none;
}

on: {
 '!click': function (e) {
 let span = document.getElementsByClassName('span')[0]
 let input = document.getElementsByClassName('input')[0]
 span.style.display = 'none'
 input.style.display = 'inline-block'
 input.focus()
 event.stopPropagation()
 },
 input: function (event) {
  self.inputValue = event.target.value // 在data中定义inputValue
 }
}

watch: {
 inputValue: function () {
  console.log(this.inputValue)
 }
 }