Abstract: U-shaped hanging ring is a type of connecting hardware used to assemble towers, conductors, and insulators together. In the process of transmission line operation, problems such as U-ring corrosion, wear and fracture often occur, and the fracture problem directly threatens the safe and stable operation of transmission lines. Therefore, it is particularly important to strengthen the analysis of U-ring fracture causes. In this paper, the causes of U-ring fracture of a 500 kV transmission line are analyzed, and the corresponding prevention suggestions are put forward to provide reference for the analysis and treatment of similar events.