/**index.wxss**/ .container{ padding: 0; } .body{ width: 100%; height: 100%; position: fixed; top: 50%; left: 0; transform: translateY(-50%); } .a_btn{ position: fixed; z-index: 99; bottom: 26%; left: 50%; transform: translateX(-50%); } .a_btn image{ height: 68rpx; }