效果图

show-overflow-tooltip

<el-table-column show-overflow-tooltip>     
    <template slot-scope="scope">
          <span class="over-content">{{}}</span>
        </template>
 </el-table-column>

css

.over-content {
  width: 80;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}