With the gradual opening of the low-altitude airspace, unmanned aerial vehicles (UAVs) have been extensively applied in diverse fields as crucial low-altitude aircraft. However, the increasing demands of complex environments and arduous tasks can hardly be satisfied using the existing single-UAV flight planning techniques. Thus, multiple UAVs cooperative operations and intelligent planning have been considered as the current research hotspots and challenging tasks. A multiple UAVs flight path planning method in a three-dimensional environment based on the starfish optimization algorithm (SFOA) was proposed for multi-UAV pre-flight path planning scenarios. The effectiveness and superiority of this algorithm in path optimization were verified through comparative experiments. The research results show that in a complex three-dimensional static environment, the SFOA demonstrates good global search capabilities and high planning efficiency, providing a new solution for multi-UAV cooperative operations.