關於該問題的layui官方文件地址：http://www.layui.com/doc/modules/form.html

<div class="layui-form-item">
<label class="layui-form-label">類別</label>
<div class="layui-input-inline">
<select id="GoodsAddModel_GoodsCategorySel" lay-verify="required" lay-search="">
@*動態新增類別*@
</select>
</div>
</div>
 

 $.ajax({
            url: "/Goods/GetGoodsCategory",
            data: {},
            type: "post",
            async: false,
            success: function (data) {
                if (data != "" && data != null) {
                    layui.use(['layer', 'form'], function () {
                        var form = layui.form;
                        var length = data.length;
                        var html1 = '<dd lay-value="" class="layui-select-tips layui-this">直接選擇或搜尋選擇</dd>';
                        var html2 = '<option value="" >直接選擇或搜尋選擇</option>';
                        for (var i = 0; i < length; i++) {
                            html1 += '<dd lay-value="' + data[i].CategoryId + '">' + data[i].CategoryName + '</dd>';
                            html2 += '<option value="' + data[i].CategoryId + '">' + data[i].CategoryName + '</option>';
                        }
                        $("#GoodsAddModel_GoodsCategorySel").next().children().eq(1).html(html1);
                        $("#GoodsAddModel_GoodsCategorySel").html(html2);
                        form.render();//沒有寫這個，操作後沒有效果
                    });

                }
            }
        });