Abstract: To solve the problem of heat dissipation issue caused by the instantaneous high-power operation of electronic equipment in ballistic environment，expanded graphite and high alcohol composites are adopted as phase change material in this paper. The phase change heat sink and module structure are integrated and optimized, which significantly improves the heat dissipation performance of the composite phase change heat sink. The optimized design is experimentally verified. The result shows that the maximum temperature of the chip is reduced to 87.3 ℃from 107.7 ℃ after integrated design and the difference between simulation result and test result is lower than 3.6%, which meets engineering requirements. This research provides a valuable reference for the design and optimization of module structure and composite phase change heat sink for high-power ballistic electronic equipment.