Abstract: As a key channel for power transmission, power transmission lines are erected in open areas through poles, which are extremely vulnerable to lightning and affect the safety and stability of power systems. At the same time, as a lightning protection method for line towers, grounding materials are buried underground all year round, making it difficult to detect their defects. Consequently, we investigated the imaging characteristics of pulsed ground penetrating radar on the basis of traditional ground penetrating radar detection methods, and proposed a ground renetrating radar (GPR) imaging processing method for detecting faults in the grounding tower of line poles. The Stolt migration method was used to image the radar detection echo, and the radar offset image was processed with the image binarization and expansion and corrosion algorithm. The Canny operator was used to carry out the pole fault identification and diagnosis. The simulation and sand pool experiment results show that the proposed grounding body defect detection technology can be employed to accurately identify whether the grounding body is broken or damaged without digging or power failure, which is helpful for the actual line lightning detection work.