Diversion in severe weather is closely related to the designation of forbidden areas and path planning algorithms. Given the large invalid area in the Graham scanning results in the construction of the diversion environment, this study proposes a delineation method of Graham parallel scanning after the area is divided into blocks. For the sudden occurrence of severe weather and complex environments, the study proposes a dynamic programming method of composite structure conducting intelligent segmentation and ant colony algorithm local search based on incremental D*Lite global planning path. The pheromone updating strategy is improved to solve the shortcomings of slow convergence speed, long time consumed, and tendency to fall into local optimum. The experimental results show that the shape of the flight forbidden areas designated by Graham parallel scanning based on the divided blocks is closer to reality, and the area is reduced to 48.1% of the original one. D*Lite-ACO, an improved ant colony fusion D*Lite dynamic path planning algorithm for composite structures, takes both the global and local area into account and controls the replanning range between the current position and the targeted point. The evaluation metrics in path length, planning time, and iteration range are improved by 1.2%, 40.7%, and 66.7%, respectively.