To ensure the best attacking effect of the air-to-ship missiles,an attack pattern extending the endgame penetration route of the missiles to underwater was proposed,referencing to the research idea of air/water trans-media vehicle,and study was made to its global path planning.Analysis was made and a model was established for the comprehensive defense capability of the ship to air and sea.Then,to guarantee the efficiency of the planning algorithm,the Multi-colony's Particle Swarm Optimization (MPSO) algorithm was used for optimal searching.The corresponding fitness function and evolutionary strategy were designed,and simulation was made.The simulation result shows that the algorithm can achieve global path planning to the weapon passing through different media.