Ensuring adequate power supply for vehicle-mounted high-power microwave sources under a wide temperature range, it is challenging for an energy storage system composed of a single type of device to achieve both miniaturization and long lifespan simultaneously. To solve this problem, this study carries out multi-objective configuration optimization based on a passive lithium-ion battery-supercapacitor hybrid energy storage system. Firstly, the equivalent circuit model and the capacity decay model of lithium-ion batteries and supercapacitors are calibrated through the test data. Then, the non-dominated sorting genetic algorithm with elite strategy is used to solve the configuration optimization problem considering the objectives of weight and life. Finally, through the simulation and analysis of the solution results, the effectiveness of the optimization model is verified. The results show that the hybrid energy storage scheme can greatly reduce the output current fluctuation of lithium-ion batteries; under the same service life and cost compared with the pure lithium-ion battery scheme, the system weight of the hybrid energy storage scheme is reduced by 10.97%, and the maximum power output at 25 ℃ is increased by 12.67%, showing significant improvement in performance.