a{text-decoration:none;color:#3DBBF5;}
   *{
    margin: 0;
    padding: 0;
   }
   .wrapper{
    width: 400px;
    height: 300px;
    margin: 100px auto;
   }
   #lunbo{
    position: relative;
    overflow: hidden;
   }
   #list{
    position: relative;
    white-space: nowrap; // 這塊用行元素模擬，所以才用該屬性，塊元素可修改這塊
   }
   #list span{
    display: inline-block;
    width: 400px;
    height: 300px;
    text-align: center;
    line-height: 300px;
    font-weight: bold;
    font-size: 100px;
    color: #fff;
   }
   #buttons{
    position: absolute;
    bottom: 0;
    text-align: center;
    width: 100%;
    height: 40px;
    line-height: 40px;
   }
   #buttons span{
    display: inline-block;
    width: 15px;
    height: 5px;
    background: #fff;
    margin: 0 10px;
    cursor: pointer;
    transition: all .5s;
   }
   #buttons span.on{
    height: 20px;
   }
   .arrow{
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    font-size: 80px;
    font-weight: bold;
    color: #fff;
    opacity: .3;
    transition: all .5s;
   }
   .wrapper:hover .arrow{
    opacity: 1;
   }
   #prev{
    left: 10px;
   }
   #next{
    right: 10px;
   }

<div class="wrapper">
   <div id="lunbo">
    <div id="list" style="left: -400px;">
     <span style="background:yellow;">5</span><span style="background: red;">1</span><span style="background:black;">2</span><span style="background:green;">3</span><span style="background:blue;">4</span><span style="background:yellow;">5</span><span style="background: red;">1</span>
    </div>
    <div id="buttons">
     <span index="1" class="on"></span>
     <span index="2"></span>
     <span index="3"></span>
     <span index="4"></span>
     <span index="5"></span>
    </div>
    <a href="javascript:;" id="prev" class="arrow">&lt;</a>
    <a href="javascript:;" id="next" class="arrow">&gt;</a>
   </div>
  </div>

window.onload=function () {
   var lunBo = document.getElementById("lunbo");
   var list = document.getElementById("list");
   var btn = document.getElementById("buttons").getElementsByTagName('span');
   var prev = document.getElementById("prev");
   var next = document.getElementById('next');
   var interval = 3000;
   var timer;
   var index = 1;
   var animated = false;
   for (var i=0;i<btn.length;i++) { //按鈕加點擊事件
    btn[i].onclick=function () {
     if(this.className=='on') //如果是狀態(tài)按鈕直接返回節(jié)約資源
     {
      return
     };
     var myIndex =parseInt(this.getAttribute('index'));//獲取按鈕的index屬性值
     var offset = -400*(myIndex-index); //根據屬性值 計算偏移量
     animate(offset)  //輪播動畫
     index = myIndex; // 改變索引值
     showBtn();   //顯示狀態(tài)按鈕
    }
   }
   function showBtn () { 
    for (var i=0;i<btn.length;i++) {
     btn[i].className=''; 
    }
    btn[index-1].className='on';
   }
   prev.onclick=function () { //上一頁事件
    if (animated) { //如果是動畫狀態(tài) 直接返回解決bug
     return;
    }
    if (index==1) { 
     index =btn.length;
    } else{
     index-=1;
    }
    animate(400); 
    showBtn();
   }
   next.onclick=function () {
    if (animated) {
     return;
    }
    if (index==btn.length) {
     index =1;
    } else{
     index+=1;
    }
    animate(-400);
    showBtn();
   }
   function animate(offset) {
    animated = true; //表示在動畫狀態(tài)
    var newLeft = parseInt(list.style.left) + offset; //計算新的left值
    var time = 400; //設置動畫總時間
    var interval = 10; //動畫幀時間
    var speed = offset/(time/interval); //每幀運動距離
    function go () { 
     if ((speed>0 && parseInt(list.style.left)<newLeft) || (speed<0 && parseInt(list.style.left)>newLeft)) { //通過條件判斷到它是否還要繼續(xù)進行動畫
      list.style.left = parseInt(list.style.left) + speed +'px';
      setTimeout(go,interval) 
     } else{
      animated = false; //動畫狀態(tài)結束
      list.style.left = newLeft + 'px'; //現(xiàn)在的位移
      if (parseInt(list.style.left)<-2000) { // 輔助假圖
       list.style.left = -400 + 'px';
      } else if( parseInt(list.style.left)>-400){
       list.style.left = -2000 + 'px';
      }
     }
    }
    go();
   }
   function play () { 
    timer = setTimeout(function () {
     next.onclick();
     play();
    },interval)
   }
   play();
   function stop () {
    clearTimeout(timer);
   }
   lunBo.onmouseover=stop;
   lunBo.onmouseout=play;
  }