In recent years, with the increasing integration of missile-borne electronic equipment and the increasing internal heat consumption, how to achieve efficient thermal management of equipment has become a major challenge restricting the further development of missile-borne electronic equipment. In this paper, a phase change heat storage module applied to high-power missile-borne microwave combination is proposed Through simulation analysis, the influence of the main structure of the thermal storage module on the overall heat storage capacity of the heat storage module is studied. After comprehensively considering various factors such as manufacturability, quality, heat storage capacity, the structural form of the heat storage module and the final phase change medium material has been confirmed. A sample of heat storage module was processed by using the additive manufacturing technology, and a thermal test platform was built to evaluate the heat dissipation effect. The experiment shows that the total heat consumption of the module is 211 W at 60 ℃, and the maximum surface temperature of the module is 104.1 ℃ after 10 min of operation, which meets the operating conditions of the microwave combination. The heat storage design technology can effectively solve the problem of high temperature rise under the conditions of short-time and high power of the module, and has broad application prospects in the field of thermal management of missile-borne electronic equipment.