Aiming at the difficulty of UAV route planning in unknown environment, a method of positioning and route planning based on switched Kalman filter (SKF) is proposed. According to multi-hypothesis theory, the map observation data is established. Combined with the route matching method based on INS/GPS/GIS multi-sensor fusion, the multi-sensor fusion and multi-model parameter estimation are completed by using SKF algorithm to realize the autonomous positioning and route of the UAV planning. Simulation results show that the proposed algorithm has good stability, fast convergence speed, low computational complexity and high accuracy of track estimation.