SOURCE

var num = 0;
//追加的元素
function add(){
    var del = document.querySelector('.del');
    del.setAttribute('onclick','deletehtml("infor'+num+'")')
    var text = document.querySelector('.content')
    var newtext = text.innerHTML
    //创建HTML对象和元素--文本格式
    var text1=document.createElement("div");
    text1.setAttribute("class", "infor");
    text1.setAttribute("id", "infor"+num);
	text1.innerHTML = newtext;
    //追加元素
	document.body.appendChild(text1);
    num++
}

//删除元素
function deletehtml(e){
    var del = document.getElementById(''+e+'');
    del.remove()
     console.log(e);

}

<div>
    <button onclick="add()">新增</button>
</div>
<div class="content" style="display:none">
    <input type="text" class="name">
    <input type="text" class="mobile">
    <input type="text" class="age">
    <div class="btn">
        <button>新增</button>
        <button onclick="deletehtml()" class="del">删除</button>
    </div>
</div>

.content,.infor{
    display: inline-flex;
    padding: 10px
}
.content input{
    width: 60px;
    height: 20px
}
.infor input{
    width: 60px;
    height: 20px
}