效果：

代码：

<span>系统词典维度：</span>
	<el-select
	  v-model="dNum"
	  placeholder="请选择"
	  multiple
	  collapse-tags //设置collapse-tags属性将它们合并为一段文字
	  size="small"
	  style="width:160px"
	  class="tags-select-input"
	>
	  <el-option
	    v-for="item in gainianOptions"
	    :key="item.uid"
	    :label="item.name"
	    :value="item.en"
	  ></el-option>
	</el-select>

css:

.tags-select-input /deep/ .el-select__tags {
  white-space: nowrap;
  overflow: hidden;
  flex-flow: nowrap;
   display:flex;
  flex-wrap:nowrap;
}
.tags-select-input /deep/ .el-select__tags-text {
  display: inline-block;
  max-width: 90px;//设置最大宽度 超出显示...
  white-space: nowrap;
  overflow: hidden;
  flex-flow: nowrap;
  vertical-align:bottom;
  text-overflow:ellipsis;
}