Abstract: In view of the large deviation of infrared temperature measurement for high voltage switchgear and the difficulty of temperature measurement for high voltage equipment, the radio frequency identification(RFID) wireless method is proposed for online temperature monitoring of high voltage switchgear. The sensor based on RFID technology is installed on the node under test, eliminating the traditional signal transmission line, and the sensor itself can obtain the power required for operation through the environment field. In order to improve the transmission accuracy of the sensor and extend the transmission distance, the RFID chip is specially designed, and the passband pulse width of the circuit is increased. Applying the temperature monitoring system to the 35 kV switch cabinet of Xuejiawan Power Supply Station can effectively monitor the temperature in the switch cabinet, and timely warn the heating fault, so as to improve the operation safety of electric equipment.