In the automobile automatic air conditioning system, the most important is the control of the temperature gradient and relative humidity in the car. The performance of the temperature and humidity sensor directly affects the performance of the air conditioning system. Because the relative humidity of the air is greatly affected by temperature changes, an integrated temperature and humidity sensor is designed for the application environment of automotive air conditioning, which is convenient for temperature and humidity measurement and the temperature difference of the refrigerant compensated by the humidity, and the refrigeration system can directly control the evaporator The refrigerant flow rate and the superheat of the evaporator outlet.