Abstract: According to present gas sensors based on the carrier catalytic element, they need zero and linear calibration by manual adjustment, resulting in a large number of waste problems of manpower and material resources. A sensor design scheme is proposed in view of PWM zero calibration. The principle and the hardware circuit are analyzed about the existing carrier catalytic element for gas concentration measurement, the hardware circuit and control algorithm are proposed based on PWM zero calibration. Finally, it is introduced that PWM calibration can be realized remotely through the CAN bus communication of gas sensor.