As an important part of power system, low-voltage distribution network is the front end of power supply to users. Its reliability and stability directly determine the quality of power supply service. With the gradual improvement of distribution network construction, customers have put forward higher requirements on the timeliness of power supply fault treatment, but efficient search of low-voltage distribution network fault has always been a difficult point in the process of distribution network repair. This paper makes an in-depth analysis of the causes of low-voltage distribution network fault in Shuangta District, Chaoyang City, and determines the causes affecting the stable operation of the line. The key factors affecting the fault location accuracy of low-voltage distribution network are line wear caused by wind and aging of joint insulation tape. The telescopic ground wire bushing fixing device is designed to effectively avoid the insulation wear of the line, and the fault locator is applied to accurately locate hidden faults, greatly improving the fault location accuracy of the low-voltage distribution network and ensuring the power supply reliability of the grid.