Abstract: The main shortcoming of the strap-down inertial navigation system (SINS) is the increasing navigation positioning errors with time. Double-star positioning system is one regional satellite positioning system built up by our country, and can output horizon position information with high accuracy, but the double-star positioning system has the characteristic of output position lag and bad concealment. This paper studies the filtering method for this integration system aiming at the position lag, and puts forward the statistical model of the measurement noise of integration system for the first time, at the same time designs the time of integration in order to compensate for the bad concealment. The simulating results show this filtering method is feasible, which has better value of engineering application.