In order to improve the safety and design of shipboard power system, the influence of spare parts configuration on the vulnerability of shipboard power network was studied. A twoobjective optimization model was proposed to reduce the cost, quality, volume and other constraints. The objectives of optimization model were norm of comprehensive vulnerability degree and resource consumption scale. The initial allocation spare parts of each node in the shipboard power network were determined according to the satisfaction rate. Then, the optimization model was optimized by the marginal optimization algorithm. The purpose of improving the network robustness of the shipboard power system was realized through the reasonable allocation of spare parts. Finally, the model and the algorithm were verified by the example of complex ring shipboard power network.