China's western terrain is dominated by mountains, plateaus and basins, and the east is dominated by plains and hills. The mountainous area occupies 2/3 of the total national area. Due to the restriction of terrain conditions, the mechanization degree of orchard management is not high, and the labor intensity of fruit farmers is large and the cost is high. The desire of fruit farmers for orchard mechanization management and protection is very urgent. This system in view of the four rotor unmanned aerial vehicle developed a terrain adaptive landing gear, analysis of the terrain recognition algorithm, combined with mountain orchard plant protection drone operation requirements, the plant protection drones take operation line extraction method, the optimal path for homework, according to the characteristics of the fruit tree distribution research combines visual simultaneous localization and mapping technology and global navigation satellite system technology level of unmanned aerial vehicle navigation control method, It is of great research and economic value to combine the above methods and build an adaptive navigation control system suitable for quadrotor plant protection unmanned aerial vehicle operation in mountain orchards, and to establish an adaptive navigation system for mountain orchard plant protection unmanned aerial vehicle.