wxml

<swiper class='banner' indicator-dots="{{indicatorDots}}"
  autoplay="{{autoplay}}" interval="{{interval}}" duration="{{duration}}">
  <block wx:for="{{imgUrls}}" wx:key="">
    <swiper-item>
      <image src="{{item}}" class="slide-image" />
    </swiper-item>
  </block>
</swiper>
<view class='wanbox'>
  <image class='wan' src='http://wechatpx.oss-cn-beijing.aliyuncs.com/qixing/ceng.png'></image>
</view>

wxss

.slide-image {
  width: 750rpx;
  height: 345rpx;
}
.banner {
  width: 750rpx;
  height: 345rpx;
}
.wanbox{position: relative;z-index: 99}
.wan {
  display: block;
  width: 750rpx;
  height: 35rpx;
  margin-top: -34rpx;
}