Abstract: Double star navigation system is one regional global navigation system (RDSS) built up by our country. The disadvantage of Double star navigation system is given and one navigation system made up of three earth synchronous satellites based on Double star navigation system is put forward. The receiver can calculate the position of user according to the three measured pseudo ranges and the altimeter's message. And the integration navigation system of Three star navigation system and SINS based on pseudo range are further studied. The simulation results show that this integration method can improve the navigation precision effectively, and is one kind of inertial/satellite integration navigation system fit for our country.