Abstract: This paper takes the communication network security of plant protection UAV as the research object, analyzes the overall application technology of plant protection UAV and UAV communication system,puts forward the influencing factors of UAV communication network security,and puts forward a network communication optimization measure of safety prediction through flight trajectory, noise injection into communication network and cooperative multi-point communication mode. The simulation results show that the optimization measures can effectively guarantee the communication data transmission security of plant protection UAV in the process of operation.