The SMD flight control and navigation system is a highly integrated and reliable system designed for the SMD VTOL fixed-wing UAV. Ensure good stability and control of the aircraft within the flight envelope. The flight control software is based on the real-time task scheduling system, and the front and rear platform architecture and modular design ensure the high reliability of the system. Modules include: navigation module, route planning and guidance module, control module, flight management module, monitoring and security protection module.