*{
    margin: 0;
    box-sizing:border-box;
}
.ClearFloat:after{
    content: "020"; 
    display: block; 
    height: 0; 
    clear: both; 
    visibility: hidden;  
}
.ClearFloat{
    zoom:1
}
html,body {
    width: 100%;
    height: 100%;
    margin: 0;
}
#container{
    width: 100%;
    border: 1px solid red;
}
.dragBox{
    width: 25%;
    height: 150px;
    padding: 5px;
    float: left;
}
.dragBox_container{
    width: 100%;
    height: 100%;
    border: 1px solid rgba(30, 193, 193, 0);
}
.dragBox_container:hover{
    background: #1EC1C1;
    border: 1px solid #1EC1C1;
}
.dragBox_container_head{
    height: 21px;
    padding: 0 5px;
    background: #93c8e0;
}
.dragBox_container_head_dragIcon{
    cursor:move;
}
.dragBox_container_head_dragIcon:hover{
    color: #1EC1C1;
}

.dragBox_container_head_title{
     padding: 0 0 0 10px;
}

.dragBox_container_head_dle{
    float: right;
    cursor:pointer;
}
.dragBox_container_head_dle:hover{
    color: red;
}
.dragBox_container_content{
    background: orange;
    height: calc(100% - 21px);
}
#dragBoxSimulation{
    position: fixed;
    z-index: 99;
    border: 1px solid #1EC1C1;
    background: rgba(193, 30, 30, 0.45);
}

<button id="add">添加拖动框</button>
<div id="container" class="ClearFloat"></div>

var dragBoxNumber=0;//只是用以计算有多少个拖动框，可有可无
var DragBoxData=null;//保存拖动框基础数据

$("#add").click(function () {
    dragBoxNumber++
    $(‘#container‘).append(
        ‘<div class="dragBox">‘+
            ‘<div class="dragBox_container">‘+
                ‘<div class="dragBox_container_head">‘+
                    ‘<span class="dragBox_container_head_dragIcon">+</span>‘+
                    ‘<span class="dragBox_container_head_title">标题:第‘+dragBoxNumber+‘个</span>‘+
                    ‘<span class="dragBox_container_head_dle">x</span>‘+
                ‘</div>‘+
                ‘<div class="dragBox_container_content">‘+
                    ‘<input value="内容:第‘+dragBoxNumber+‘个">‘+
                ‘</div>‘+
            ‘</div>‘+
        ‘</div>‘
    )
});

$(document).on(‘click‘, ‘.dragBox_container_head_dle‘, function(){
    $(this).parent().parent().parent().remove()
});

$(document).on(‘mousedown‘, ‘.dragBox_container_head_dragIcon‘, function(e){//点击
    var _this=this;
    var optionContainer=$(_this).parent().parent();
    var optionW=optionContainer.width();
    var optionH=optionContainer.height();
    var x=e.pageX;
    var y=e.pageY;
    var box=$(optionContainer.parent())
    //console.log({optionW,optionH,x,y});
    DragBoxData={
        box,
        domIndex:$(".dragBox").index(box),
        width:optionW,
        height:optionH,
    }
    var dragBoxStyle=[
        "width:"+optionW,
        "height:"+optionH,
        "left:"+x,
        "top:"+y,
    ].join(";");
    $("body").append(
        ‘<div id="dragBoxSimulation" style="‘+dragBoxStyle+‘"></div>‘
    )
    document.onselectstart=function(){return false}//禁止拖动选择文字
});
document.onmousemove=function(e){//拖动
    e=e||event;
    if(DragBoxData){
        var optionW=DragBoxData.width
        var optionH=DragBoxData.height
        var x=e.pageX;
        var y=e.pageY;
        $("#dragBoxSimulation").css({
            width:optionW,
            height:optionH,
            left:x+2,
            top:y+2,
        })
    }
};
document.onmouseup=function(e){//释放
    if(DragBoxData){
        var x=e.pageX;
        var y=e.pageY;
        //console.log({x,y});
        var option=$(".dragBox")
        for (var i = 0,iLen=option.length; i < iLen; i++) {
            var element = $(option[i])
            var w=element.width();
            var h=element.height();
            var l=element.offset().left;
            var t=element.offset().top;
            if (x>l&&x<l+w&&y>t&&y<t+h) {
                //console.log({w,h,l,t});
                //console.log(element);
                var thisIndex=$(".dragBox").index(element)
                if (thisIndex==DragBoxData.domIndex) {//相同就不用做任何处理
                    break
                }
                $(".dragBox")[DragBoxData.domIndex].remove()
                if (x<l+(w/2)) {//前
                    element.before(DragBoxData.box)
                }else{//后
                    element.after(DragBoxData.box)
                }
                break
            }
        }
        $("#dragBoxSimulation").remove();
        DragBoxData=null
        document.onselectstart=function(){return true}//解除禁止拖动选择文字
    }
};