Aiming at the thermal safety problem caused by insufficient heat dissipation of the power battery module at a high discharge rate, taking a prismatic lithium-ion battery as the research object, a cooling structure of battery thermal management system embedded with aluminum heat pipe-aluminum plate is designed. An orthogonal test scheme with four factors and three levels is established. The analysis method combining the Range method and the Hierarchy method is adopted to study the heat dissipation performance of the battery module under natural convection. The effect of multi-parameter coupling with fin number, fin position, fin pitch, and fin size of the condensing section of heat pipe on the maximum temperature of battery module coupling is analyzed at the 3C discharge rate. The results indicate that the order of influence weights of various parameters on the maximum temperature of the battery module is as that: fin number fin size > fin position > fin pitch. The optimum parameter combination of the fin is A3B2C3D3. Under the environment of natural convection, appropriately reducing the fin pitch can not only ensure the heat dissipation efficiency but also benefit the compactness of the battery heat dissipation system. Furthermore, different convective heat transfer conditions are compared and analyzed. When the convective coefficient of a fin is 55 W·m-2·K-1，and the fin pitch is 9 mm，the maximum temperature of the battery module is 40.57 ℃, and the maximum temperature difference is 3.89 ℃，with the optimal parameter combination of the fin even discharged under 3C accelerated working condition.