Abstract: Land combat vehicles are inevitably subject to the vibration disturbance by wind gust or engine idling, etc. in the stationary initial alignment process of the Strapdown Inertial Navigation System (SINS). Obviously, it’s necessary to consider the impact of vibration disturbance during the alignment process to achieve better performance. In order to guarantee the alignment accuracy on the rocking base and shorten the convergence time of alignment, a gyrocompass alignment method of SINS based on Kalman filter pretreatment and dynamic gain adjustment was proposed. The output of gyros and accelerometers was firstly pre-filtered by Kalman filter to remove the impact of high-frequency small-amplitude rocking interference. The low-frequency large-amplitude rocking interference on vehicle was tracked through dynamic gain adjustment of gyrocompass alignment. The vehicle test of a ring laser SINS showed that the new gyrocompass alignment method can suppress high-frequency disturbances when the vehicle underwent low-frequency large-amplitude rocking interference. And the alignment process can track the attitude change of vehicle caused by low-frequency large-amplitude rocking interference. Comparing with traditional gyrocompass alignment algorithm and Kalman filter alignment method, the performance of the new gyrocompass alignment method is much improved by filtering random noise caused by vibration disturbance of vehicle effectively.