Abstract: The improved and simplified method of the wave algorithm in the dynamic system is investigated. Random disturbances such as gyro drift and accelerometer error are described in non statistical way. And Kalman filter is applied subtly to filter the wave disturbance in integrated navigation system. By simplifying the original algorithm, the amount of calculation is decreased. By the comparison between the new algorithm and Kalman filter applied in inertial/GPS integrated navigation system, and according to the computer simulation, it is shown that the new improved algorithm is almost as effective as the original, and the estimation precision of the new algorithm for the random wave disturbance is better than the standard Kalman filter.