Abstract: As the core component of the power conversion of the energy storage converter, the power module will generate a lot of heat during operation, and excellent heat dissipation is the key to ensure the reliable operation of the equipment. The performance improvement of the power module cooling system of the energy storage converter is studied by numerical simulation and experimental verification. Numerical analysis method was used to compare the heat transfer performance improvement effects of 7 system variables, extract the best parameter combination, and create an optimization model. The results show that the heat dissipation performance of the radiator is the main factor affecting the heat dissipation performance of the system. Compared with the original model, the maximum heat dissipation optimization degree of the optimized model is 13%, and the maximum heat source temperature is reduced by 6 ℃. The performance of the optimized model was verified by establishing a 1∶1 experimental model,the experimental results show that the heat dissipation optimization degree is 11%, and the maximum heat source temperature is reduced by 4 ℃, which verifies the heat dissipation performance improvement effect of the optimization model.