Abstract: Objectives The ship power system (SPS) is inevitably in a non-complete state during combats and requires reconfiguration. At this point, the inertia of SPS is small, and the connection of vital loads, mainly high-power impulse loads, will cause frequency instability or even collapse of SPS, making it difficult to complete the established tasks of the ship. Methods In order to ensure the frequency security of SPS after the impulse loads are connected, a flexible loads switching strategy is proposed firstly, based on the adjustability characteristics of flexible loads’ power. During the access/exit of the impulse loads, the flexible loads are cut off/put in to maintain the frequency within safe range. Then, the SPS frequency security boundary is determined based on the flexible load switching strategy, which is converted into constraint conditions, and SPS reconfiguration strategy adapted to the access of impulse loads is proposed. Results The simulation of different power impulse load access scenarios shows that this strategy can maintain frequency safety. And compared with different reconfiguration strategies, the proposed strategy has the highest impulse load power for access. Conclusions Therefore, this strategy not only maximizes the weighted recovery load power, but also considers the role of flexible loads and battery energy storage system (BESS) in maintaining safe operation of impulse loads, ensuring successful access of important impulse loads. Finally, the effectiveness and superiority of the proposed strategy are verified by simulation.