Automobile air conditioning refrigeration system is composed of compressor, condenser, evaporator, air conditioning pipeline, etc. Refrigerant in the air conditioning system repeatedly in the four processes of compression, condensation, expansion, evaporation to achieve refrigeration in the car; It is mainly controlled by electromagnetic clutch, compressor temperature sensing package, ECU, high and low voltage switch, relay, evaporator temperature sensor, AC switch, blower motor, fan motor and other components.