As the surface temperature of evaporator in cold storage is lower than 0℃, with the increase of cooling time, frost layer will appear on the outer surface of cold storage air cooler, which will not only seriously affect the heat transfer coefficient of cold storage air cooler, but also greatly reduce the circulating air volume of cold storage air cooler. This will seriously affect the heat exchange of the cold air blower in the cold storage, and the running performance of the cold storage equipment will be seriously reduced. In order to ensure the good heat transfer performance of the cold storage fan, it is necessary to defrost the cold storage fan. At present, the most common defrosting method of cold storage fans is electric heating defrosting. Electric defrosting has the advantages of complete defrosting and automatic control. The distance between the back of the cold storage fan and the cold storage insulation board is at least 300MM, which is beneficial to the air circulation of the cold storage and convenient for future maintenance. A U-shaped oil return elbow should be set at the air return port of the cold storage blower to facilitate the return of frozen oil to the cold storage compressor. The outlet pipe of the cold storage blower should be provided with a U-shaped elbow to form a liquid seal to avoid air circulation inside and outside the warehouse.