In order to improve the precision of AUV navigation orientation and research the application of SINS/DVL combined navigation system in the large voyage AUV. Firstly, the model of analyzing error will be established. Secondly, calculate the error by the normal kalman filter equation; lastly, use simulation to analyze the error by the normal kalman filter arithmetic with known system yawp and observation yawp. The result indicates that error array will be not non-negative definite any more because the filter is divergent obviously, it will make influence the filter increment.