Abstract: In this paper, the inertial navigation system and array antenna is applied in GPS receivers to improve the whole performance of navigation system. The structure and mathematical model of tightly coupled GPS/INS integration is detailedly analyzed, whose extended kalman filter (EKF) algorithm is given. The principle and technique of anti-jamming processing based on array antenna is described. And then, the navigation system model combing GPS/INS and array antenna is put forward. Finally,the output carrier to noise ratio (C/N0) is simulated and analyzed, which shows this scheme can mitigation effectively the interference signals and assure the normal working of navigation system.