HTML代码

<el-date-picker
  v-model="value1"
  type="datetimerange"
  range-separator="至"
  start-placeholder="开始日期"
  format="yyyy-MM-dd hh"
  value-format="yyyy-MM-dd hh:mm:ss"
  popper-class="tpc"
  end-placeholder="结束日期">
</el-date-picker>

CSS样式

<style>
.tpc .el-time-spinner__wrapper {
  width:100% !important;
}
.tpc .el-scrollbar:nth-of-type(2) {
  display: none !important;
}
</style>

效果图