<div class="layui-input-block" style="width:200px" >
                    <select name="goodsTypeId" lay-filter="parentTypes"  >
                        <option value="0" th:each="t:${types1}" th:value="${t.goodsTypeId}" th:text="${t.typeName}">寫作</option>

                    </select>
  </div>

<script>
form.on('select(parentTypes)', function(data){
                 let pid = data.value;
                 console.log(pid);
                 let types = [[${types1}]];
                 console.log(types);
            });
</script>

其中后臺傳過來的${types1}為List<GoodsTypeVO>
前端報錯：ReferenceError: Can't find variable: GoodsTypeVO

已解決：
加上th:inline='javascript'

<script th:inline='javascript'  type="text/javascript">
form.on('select(parentTypes)', function(data){
                 let pid = data.value;
                 console.log(pid);
                 let types = [[${types1}]];
                 console.log(types);
            });
</script>

問題即解決。