Plastic film covering refers to a measure of covering the ground with agricultural plastic films. It has the function of reducing the impact of rain drops, preventing erosion and crust formation; It can effectively reduce evaporation of soil water, preserve soil moisture during drought, and increase soil moisture after rain, promote crop absorption and growth of water, and improve soil water utilization efficiency; It can keep the soil at a suitable temperature and humidity, slow down the ground temperature and maintain it for a long time, which is conducive to the ripening and decomposition of fertilizers, and improve the soil fertility. Plastic film mulching is a common measure that can not only prevent soil erosion but also improve crop yield due to its low cost, convenient use, and large yield increase.