Abstract: The low earth orbit (LEO) spacecraft has high requirement for the stability of navigation system. If the standard Kalman filter is used to the integrated navigation system, large errors might occur and the navigation accuracy of the LEO spacecraft will decrease when abnormal disturbances occur. Hence, an adaptive robust filter is proposed to apply to the navigation system of LEO spacecraft, and then the INS/CNS/GNSS integrated navigation is designed based on it. To verify the effectiveness of the adaptive robust filter, simulation experiments are implemented respectively for the integrated navigations with the standard Kalman filter and adaptive robust filter.