el-upload组件声明 图片样式 为 picture-card

list-type="picture-card"

修改样式

.avatar-uploader-icon {
font-size: 28px;
color: #8c939d;
width: 148px;
height: 148px;
line-height: 148px;
text-align: center;
}
.avatar {
width: 148px;
height: 148px;
display: block;
}