Aiming at the problem of the descending filtering precision of filter with single fixed parameter, which is generated by the integrated navigation system’s model parameter change deduced by complex environment, study the multi-sensor integrated navigation system based on interacting multi-mode. Give state fusion estimation formula based on all information, use kalman filter algorithm of interacting multi-mode into SST/GPS/SINS multi-sensor integrated navigation system and compare it with single model kalman filtering algorithm. The simulation result shows that the method can improve integrated navigation system’s filtering precision and reliability. But the system filter precision will decrease when practical model collection cannot cover all models.