Abstract: Aim to route planning for UAV, the particle swarm optimization algorithm was improved by changing inertia weight and using self-adaption coding means, the maximum horizontal swerving angle, maximum climbing/gliding angle, minimum flight-path step, minimum flight height, and the shortest flight-path distance are taken as evaluation indexes of the adaptability function.The constraint condition and the general configuration of the earth′s surface and threaten information was imported to the function of adaption, It used to solve the problem that PSO easily falls into a local the extremum.The simulation results show that this method can meet the online route planning.