Abstract: Double star position system is one kind of regional position system build up. The position principle of Double star position system is introduced, and its shortcoming that is the bad real time of position is explained. For this fact one scheme that the output velocities of SINS after revised by the Kalman filter modify the output level positions of Double star navigation system is put forward, then the Double star position system is integrated with the inertial system, and the state and measurement equations are build up. The simulation results demonstrate this method is feasible, and has an important theoretic value for the practical use of the Double star navigation system.