Abstract: The rapid development of clean and renewable energy technologies represented by wind and solar energy, as well as the continuous growth of load demand, have put forward higher requirements for the safe operation of the power equipment. The performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding, transportation, assembly, and operation, which cannot meet the reliability requirements of power systems in the new situation. Nondestructive detection is an essential technical method in industrial development, which can detect and evaluate the defect and damage status of in-service equipment, key components, and materials without damaging the object.