In order to understand the cause of the fault of transmission line equivalent parallel clamps more clearly, it needs real-time monitoring of the temperature of the clamp. According to the structure of the model and the principle of heat transfer overhead line clamp, a parallel groove clamp steady-state thermal circuit model is established to study the overall temperature distribution. By using the finite element, the temperature distribution of cross-sectional portion of the parallel groove clamp is simulated in different environmental conditions. The steady-state temperature of the parallel groove clamp at different measurement points is verified by experiments. The results of this experiment show that the maximum error between the finite element simulation and experimental results is within ± 5%, and the validity of the model is verified. It also provides a theoretical basis for further accurate calculation of the actual internal temperature of the clamp and understanding the clamp fever situation.