The lead seal is an important component of high-voltage cable terminals. Internal defects such as pores or cracks may occur due to poor installation quality or external forces during operation. To mitigate the potential risks to the safe operation of the power grid posed by lead seal defects, this paper proposes an ultrasonic detection method for detecting such defects. Based on the structural characteristics of the cable terminal lead seal, the method in this study adopts COMSOL simulation software to perform ultrasonic simulations on typical defects of high-voltage cable terminal lead seals, revealing the propagation characteristics and patterns of ultrasonic waves in lead seal defects. This study also conducts ultrasonic detection experiments on lead seal samples with artificial defects. The results show that ultrasonic waves reflect and transmit at pore defect locations, and defects at different positions can be accurately identified through defect echo time and amplitude. This method verifies the feasibility of applying ultrasonic detection technology to detect lead seal defects in cable terminals and provides a reference for detecting such defects.
