html：

css:

.drag{
width: 100px;
height: 100px;
position: absolute;
top: 0;
left: 0;
background-color: red;
}

js：

// 拖动div元素  
let vm1 = new Vue({  
    el:'#app1',  
    // 自定义指令  
    directives:{  
        drag(el,bindings){  
            el.onmousedown = function(e){  
                var disx = e.pageX - el.offsetLeft;  
                var disy = e.pageY - el.offsetTop;  
                document.onmousemove = function (e){  
                    el.style.left = e.pageX - disx+'px';  
                    el.style.top = e.pageY - disx+'px';  
                }  
                document.onmouseup = function(){  
                    document.onmousemove = document.onmouseup = null;  
                }  
            }  
        }  
    }  
})