Make a snow mat on the snow, with a thickness of 0.3 meters, a width of 4 meters, and an unlimited length. Put a layer of cabbage on the snow mat, and then lay a layer of snow 0.1 meters thick on the cabbage. This layer of snow a layer of cabbage, a total of 3 to 4 layers of cabbage, the top layer covers 1 meter thick snow. It is covered with 0.5m thick sawdust, straw ash or straw. This method can be stored until the snow is opened.