Abstract:The paper’s background is the “regional-positioning” and “seamless- positioning”, it is consist of the three systems, respectively is the regional wireless, satellite and strapdown inertial system. Among them, the inertial positioning system strong autonomy can continuously output the needed navigation information in the short term. But for a long time, its error has a sharp increase. Adopting the method which combines the navigation positioning system with others can solve this problem. Finally, car experiment was made to prove it has environmental adaptability, good fault-tolerant.