post the code:
html:

    <section class="pc-banner">
        <div class="swiper-container">
            <div class="swiper-wrapper" >
                <div v-for="( item,index ) in bannerList" :key="index" class="swiper-slide swiper-no-swiping" style="cursor:pointer;">
                    <img :src="item.serviceImg">
                    <!-- <div class="layer-mask" @click="btnBanner(item)" ></div> -->
                </div>
            </div>
            <div class="button">
                <div class="swiper-button-prev"></div>
                <div class="swiper-button-next"></div>
            </div>
        </div>
        <!-- <div class="swiper-pagination"></div> -->
    </section>

data:

        return{
            bannerList: [], 
        }

declare swiper:

        initSwiper () {
            console.log(this);
            var _this = this;
            var swiper = new Swiper(".swiper-container",{
                autoplay: false,
                autoplayStopOnLast: true,
                speed:1500,
                autoplayDisableOnInteraction: false,
                loop: true,
                noSwiping:true,
                centeredSlides: true,
                slidesPerView: 2,
                pagination: ".swiper-pagination",
                paginationClickable: true,
                prevButton: ".swiper-button-prev",
                nextButton: ".swiper-button-next",
                onClick: function(swiper,e){
                    console.log(swiper.activeIndex,e.target,"Swiper",_this.btnBanner(swiper.activeIndex));
                },
                preventLinksPropagation: false,   // 
                onInit: function(swiper) {
                     console.log(swiper.slides[2].className)
                    swiper.slides[2].className = "swiper-slide swiper-slide-active";
                },
                breakpoints: {
                    668: {
                        slidesPerView: 1,
                    }
                }
            });
        }