<div class="button">
    <span>立即下载</span>
</div>

.button {
    width: 200px;
    height: 46px;
    line-height: 46px;
    background: #2e82ff;
    color: #ffffff;
    font-size: 18px;
    border-radius: 27px;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.button:before {
    content: "";
    position: absolute;
    left: 0px;
    width: 100%;
    height: 100%;
    background-size: 20px 20px;
    background-image: linear-gradient(135deg, rgba(255, 0, 0, 0.1) 0%, rgba(255, 0, 0, 0.1) 25%, rgba(255, 255, 255, 0.1) 25%, rgba(255, 255, 255, 0.1) 50%, rgba(255, 0, 0, 0.1) 50%, rgba(255, 0, 0, 0.1) 75%,rgba(255, 255, 255, 0.1) 75%, rgba(255, 255, 255, 0.1) 100%);
    animation: moveblock 0.5s linear infinite;
}
@keyframes moveblock{
    0% {
        background-position: 0px 0px;
    }
    100% {
        background-position: 20px 0px;
    }
}