The cold storage unit is composed of a refrigerating compressor, a condenser, a compressor oil separation device, a liquid storage device, a gas-liquid separation device, a solenoid valve, a pressure control device, and a heat dissipation motor. The cold storage unit can be assembled according to the actual cold demand and different refrigerating devices required by the customer. The refrigeration capacity of the cold storage unit can be between 1KW and several hundred KW, which can meet various cold occasions.