An independently integrated navigation system using odometer(OD) to assist the strapdown inertial navigation system(SINS/OD) is discussed.In this paper,the OD error equations are proposed in detail.The observed quantity of the SINS/OD is the velocity's differences between SINS and OD,and the SINS/OD also adopts a closed kalman filter to estimate and correct the errors.The results of simulation indicate that the SINS/OD can effectively eliminate the following errors of navigation parameters:attitude,velocity,latitude and longitude etc.