Partial discharge fault is a common type of equipment fault in power system. With the continuous development of partial discharge fault, it will lead to more serious insulation deterioration and even insulation breakdown fault, leading to serious power failure.When partial discharge occurs, with the rapid transfer of local charge, it will emit ultrasonic signals in addition to electromagnetic pulse, ultraviolet, local heating and other phenomena.By detecting the ultrasonic energy distribution in the power equipment, the moderator can quickly diagnose whether the partial discharge fault has occurred or not.