Infrared thermography is an effective means to detect thermal defects in high-voltage electrical equipment and ensure safe and stable operation of the equipment. Infrared technology can be used without direct contact with high-voltage electrical equipment to detect excessive temperature areas based on the temperature distribution on the surface of the equipment itself, and detect equipment faults without stopping the operation of the equipment. Therefore, this paper is based on the technical characteristics of infrared thermography in high-voltage electrical equipment fault diagnosis, and introduces the advantages of infrared detection technology, and gives a variety of illustrations to realize infrared thermography in high-voltage electrical equipment fault diagnosis.