实现的效果如下图

 1、html

	<view v-if="item.photo_list && item.photo_list.length !== 0" :class="getImageClass(item.photo_list.length)">
		<view v-for="(j,ind) in item.photo_list" :key="'photo'+ind" class="image-wrapper">
			<img :src="j" alt="" srcset="" @click="ClickImage(item.photo_list,j)" />
		</view>
	</view>

2、js

// 图片布局
			getImageClass(total){
					  if (total === 4 ) {
					  	 return 'images';  
					  } 
					  return 'image'; 
			},

3、css

	.image {
		display: flex;
		flex-wrap: wrap;	
		align-items: flex-start;
	}
	.image .image-wrapper {
		margin: 5px; 
		width: calc(33% - 10px);
	}
	.images{
		display: flex;
		flex-wrap: wrap;	
		align-items: flex-start;
		width: 70%;
	}
	.images .image-wrapper{
		margin: 5px; 
		width: calc(50% - 10px);
	}
	.image-wrapper img {
		width: 100%;
		padding: 0;
		margin: 0;
		height: 206rpx;
		object-fit: cover;
	}