When power supply is insufficient in power system, the system stability can be warranted by shedding the excess loads. An optimal load shedding method is proposed for power supply shortage on the aircraft electric power system. The load shedding problem is formulated to the multi-objective optimization problem. The load weight priority factor is introduced into the load equation. To solve the optimization problem, the blindness and randomness of load shedding are avoided and the power supply priority of the vital loads is satisfied. Experiment results show the correction and effectiveness of the proposed method.