Abstract: Tension clamp is a kind of hardware used to fix conductor or lightning conductor on the tension insulator string of non-linear tower. In the process of transmission line operation, problems such as corrosion, heating and fracture of tension clamp often occur. Clamp fracture is a direct threat to the safe and stable operation of transmission lines. Therefore, it is particularly important to strengthen the fracture analysis of tension clamp. In this paper, the causes of the root fracture of the drainage plate of a 500 kV line conductor tension clamp are analyzed, and the corresponding treatment and prevention suggestions are put forward, which can provide reference for the analysis and treatment of similar incidents.