Abstract: The integrated navigation system has become an important accessorial equipment in modem ship's navigation system, and is developing in the direction of multi-integrated navigation system. In order to ensure the precision and reliability, this paper designs the GPS/Loran C/SINS/AHRS integrated system. In this integrated system, the self-adaptive federated Kalman filter is introduced to revise strap-down inertial navigation system (SINS); the heading angle attitude and heading reference system (AHRS) is used to ensure the convergence of heading angle; and the coordination transformation for Loran C is applied to eliminate the constant error of Loran C. The results of practical static and dynamic experiment show that this system is feasible and can meets the need of mission and engineer realization.