这个解决方案对我有用。与您的代码的唯一区别是我在类列表中添加了“搜索”。
<div id="your_elmnt_id" class="ui fluid search selection dropdown">
<input type="hidden" name="your_elmnt_id">
<i class="dropdown icon"></i>
<div class="default text"> comune </div>
<div class="menu">
<div class="item" data-value="1"> item 1 </div>
<div class="item" data-value="2"> item 2 </div>
<div class="item" data-value="3"> item 3 </div>
<div class="item" data-value="4"> item 4 </div>
<div class="item" data-value="5"> item 5 </div>
</div>
</div>
$("#your_elmnt_id").dropdown('设置选中', selected_item);