先看效果

模板文件

<transition name="myfade">
    <router-view></router-view>
</transition>

样式文件

/* myfade  */
.myfade-enter, .myfade-leave-to {
    opacity: 0;
}
.myfade-leave, .myfade-enter-to {
    opacity: 1;
}
.myfade-enter-active {
    transition: opacity .5s;
    transition-delay: .3s;
}
.myfade-leave-active {
    transition: opacity .3s
}