第一种方式

html1代码

<div class="layui-form-item">
            <label class="layui-form-label">所在行业</label>
            <div class="layui-input-block col-8">
                <select name="enterprise_type_id" lay-filter="enterprise_type">
                    <option value="-1">无</option>
                    {volist name='enterprise_types' id='vo'}
                    <option value="{$vo.id}" {if isset($data.template) && $vo.id == $data.template.enterprise_type_id}selected{/if}>{$vo.name}</option>
                    {/volist}
                </select>
            </div>
        </div>
        <div class="layui-form-item">
            <label class="layui-form-label">企业模板</label>
            <div class="layui-input-block col-8">
                <select name="enterprise_template_id" lay-filter="enterprise_template" id="enterprise_template">
                    {if $data['template']}
                    <option value="{$data['template']['id']}">{$data["template"]['name']}</option>
                    {/if}
                </select>
            </div>
        </div>

js

layui.use(['form'], function () {
        let form = layui.form
            , layer = layui.layer
            , $ = layui.jquery;
        form.render();

form.on('select(enterprise_type)', function (data) {
            let id = data.value;
            $.get(`/api/index/admin/enterprise_template/templates?name=skip&enterprise_type_id=${id}`, function (res) {
                console.log(res)
                let options = "";
                let templates = res.data;
                for (let template of templates) {
                    console.log(template)
                    options += `<option value="${template.id}">${template.name}</option>`;
                }
                console.log(options)
                $("#enterprise_template").html(options);
                form.render('select');
            }, 'json');
        });