An algorithm based on the special requirement of the autonomous underwater vehicle(AUV) navigation system is designed.The center processor unit and inertial measurement unit are selected.The principle of designing the Kalman filter is put forward.Choosing appropriate estimates and measurements,building up the equation of estimate and measurements,the centralized Kalman filter is designed.The algorithm make sure the navigation system is stable in a long time run and make full use of all the sensors' informat...