Unmanned target drone is an air target used to test the performance of airborne weapon systems. It can be used as a target of an imaginary enemy for all kinds of artillery, missiles and aircrafts in air defense or air combat training. The navigation system is the core unit of an unmanned target drone. It mainly consists of a high-precision GNSS positioning board, a high-dynamic GNSS antenna, an altitude and heading sensor, a vertical gyroscope and a flight control computer. The high-precision data of position, velocity and time, provided by the built-in GNSS positioning boards and antennas that are compatible with Beidou navigation system, combines with the data from the altitude and heading sensor, vertical gyroscope, flight control and telemetry transmitter, to provide accurate and reliable navigation data for the target drone.