In order to improve the sub-filter filtering accuracy and optimize the information fusion algorithm, an adaptive Kalman filtering algorithm based on online adjustment factor is proposed. First of all, discuss the theoretical basis of using Kalman filter technology, and design SINS/GPS tight integrated navigation system.An improved adaptive Kalman filter algorithm is proposed. By constructing an adaptive parameter factor and using the ratio of the measured noise covariance matrix to the adaptive parameters, the online correction measurement noise covariance matrix is realized. Through the result of MATLAB simulation, its position error and speed error are significantly reduced, compared with traditional tightly integrated navigation systems based on standard Kalman filter algorithm, so as to improve the positioning accuracy of the integrated navigation system and optimizing information fusion algorithm.