Integrating several kinds of navigation systems together is an effective way to increase the performance cost ratio of the navigation system. With the development of information fusion technology, the federated filtering becomes more and more attractive in navigation field, since the federated Kalman filter can be flexibly used in designing the integrated navigation system with high precision or best fault-tolerance capability. Based on the study and analysis of the algorithm and the characteristic in structure of the federated Kalman filter, a project of GPS/INS/TAN integration navigation system is presented, in this project the good fault-tolerance can be guaranteed, simultaneously the high precision and the operation tempo can also be taken into consideration. In this paper the mathematic model of GPS/INS/TAN integration navigation system is established, simulated and analyzed. The result indicates that this project is an effective way to improve the precision of navigation.