Abstract: Heat dissipation performance of power switchgear is one of the important factors affecting the safe and stable operation of power system. Considering the convection and radiation heat transfer of power switchgear, the coupled thermal-fluid model of power switchgear was established by the finite element analysis method. The temperature field of power switchgear was simulated and analyzed, and the simulation results were compared with the experimental results to verify the accuracy of the model. On this basis, the effects of vent area ratio, busbar spacing and deflection angle on busbar heat dissipation performance of power switchgear were analyzed. The results show that the vent area ratio has little effect on the busbar heat dissipation in power switchgear, while the busbar spacing and deflection angle have obvious effect on the busbar heat dissipation in power switchgear. When the busbar deflection angle is 45° and the vertical spacing and horizontal spacing are 150, 50 mm respectively, the average temperature reduction of the three-phase busbar surface is the largest, which is 4.10, 4.85, 2.08 K respectively.