body { font-family:"Microsoft Yahei"; }
body,ul,li,img,h3,dl,dd,dt,h1{margin:0px;padding:0px;list-style:none;} 
img{vertical-align: top;}
/***大图切换***/
.scroll_view{margin: 0px auto;overflow:hidden;position: relative;}
.photo_view li{position:absolute;width: 100%;}
.photo_view li em,.photo_view li h3{position: absolute;bottom: 0px;z-index: 1;height: 35px;line-height: 35px;width: 100%;left: 0px;}
.photo_view li em{z-index: 1;background:rgba(0,0,0,0.5);filter: progid:DXImageTransform.Microsoft.gradient( GradientType = 0,startColorstr = '#50000000',endColorstr = '#50000000');_background:#000;}
.photo_view li h3{z-index: 2;text-indent: 1em;font-weight: normal;}
.photo_view li h3 a{color:#fff;}
.photo_view li h3 a:hover{color:#f60;}
.small_photo{position: absolute;bottom: 40px;right: 10px;cursor: pointer;z-index: 4;}
.small_photo li {float: left;padding-right: 10px;}
.small_photo li img{width: 80px;height: 35px;border: solid 2px #ccc;border-radius: 2px;}
.small_photo li.active img{border: solid 2px #f60;}

<!-- start:大图切换 -->
<div class="scroll_view">
 <ul class="photo_view">
  <li><img src="images/ad1.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果1</a></h3></li>
  <li><img src="images/ad2.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果2</a></h3></li>
  <li><img src="images/ad3.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果3</a></h3></li>
  <li><img src="images/ad4.jpg" alt="" class="" /><em></em><h3><a href="javascript:void(0);">图片效果4</a></h3></li>
 </ul>
 <ul class="small_photo"></ul>
</div>
<!-- End:大图切换 -->

$.fn.extend({ 
 imgScroll:function(options){  
  var def={phtot_parent:$(".scroll_view"),photo_view:$(".photo_view"),small_photo:$(".small_photo"),speed:800,isauto:true,width:800,height:349},
   opt=$.extend({},def,options),
   $photo_view=opt.photo_view,
   $small_photo=opt.small_photo,
   speed=opt.speed,
   isauto=opt.isauto,
   index=0,
   _length=$photo_view.find("li").length,
   strTime=null;
  opt.phtot_parent.css({width:opt.width,height:opt.height});
  $photo_view.find("li:not(:first)").hide()//.find("img").hide();
  $photo_view.find("li").each(function(i){
   $small_photo.append('<li><img src="'+$(this).find("img").attr("src")+'" alt="" class="" /></li>');
  })
  $small_photo.find("li:first").addClass("active");
  //小图鼠标动作
  $small_photo.find("li").bind("mouseenter",function(){ 
   clearInterval(strTime);
   if(index!=$(this).index()){
    index=$(this).index(); 
    animate(index)
   }
  }).bind("mouseleave",function(){   
   if(isauto){
    start(); 
   }
  });
  //大图悬停动作
  $photo_view.find("li").bind("mouseenter",function(){ 
   clearInterval(strTime);   
  }).bind("mouseleave",function(){   
   if(isauto){
    start(); 
   }
  });
  //自动播放
  if(isauto){
   start(); 
  }
  //启动自动播放
  function start(){
   strTime=setInterval(function(){
    index >= _length-1 ? index=0 : index++;
    animate(index);
   },speed);
  }
  //动画效果
  function animate(_index){//console.log(_index)
   $small_photo.find("li").eq(_index).addClass('active').siblings().removeClass("active");//改变小图导航样式
   $photo_view.find("li").eq(_index).css("z-index",1).siblings().css("z-index",0);//控制absolute的层级
   $photo_view.find("li").eq(_index).show().find("img").css({"opacity": 0}); //装大图的opacity设置为0 
   $photo_view.find("li").eq(_index).find("img").animate({opacity:1},300,function(){
    $(this).removeAttr("style");//动画之后删除opacity
    $photo_view.find("li").eq(_index).show().siblings().hide();//显示大图 
   });//展示当前显示动画
  }
 }
});

<script type="text/javascript">
 $(function(){$("scroll_view").imgScroll({photo_view:$(".photo_view"),small_photo:$(".small_photo"),speed:3000,isauto:true}); 
 })
</script>