在textarea里加入
style="overflow-y:hidden;" onpropertychange="this.style.height=this.scrollHeight + 'px'" oninput="this.style.height=this.scrollHeight + 'px'"
示例:
<textarea name="" id="reply" cols="" rows="3" class="input-item" placeholder="回复评价" maxlength=200 style="overflow-y:hidden;" onpropertychange="this.style.height=this.scrollHeight + 'px'" oninput="this.style.height=this.scrollHeight + 'px'"></textarea>