As it has changed gradually from more electric aircraft (MEA) to all electric aircraft, the stabilization of the on-board dc power system is a hot research topic in recent years. In such an application, small and light systems are required, and thus, the optimization of passive LC filter is a significant issue. It is known that reduction of the LC filter capacitor will cause instability when the constant power load is employed. There is always a compromise between stability margin and system size. A practical method using the current perturbation was proposed in order to stabilize the on-board power system. The main objective is to suppress the instability and improve the stability margin, while keeping the benefits of the low weight and volume. The mathematical model of the system is analyzed, and the simulations and experimentations are performed to confirm the validity and effectiveness of the proposed method.