Abstract: The basic problem about the data synchronization is described and a new data syn-chronization method by software technology completely is presented which is easy to be realized.Firstly,the new method maps and unifies two data of measurement of GPS receiver and INS in the same time benchmark.Secondly,the update time difference of asynchronous data is obtained by computing the time difference when they are accepted by the computer and the time at which computer accept the data is gained by using time stamps technology.Thirdly,the interpolation method is used to get hypothesized measurement values of INS at the time when the data from GPS receivers are updated.Finally,the simulation results show that the method is feasible and effective.