With the continuous improvement of the formation cooperative and aerial refueling needing of the relative navigation function, however, the former information process methods of relative navigation have rigorous demand about the frequency and the time delay of the navigation parameter transmitting between the different platforms, and the above problems affect the stability of relative navigation function in a certain extent. Accordingly, an information process method of relative navigation is studied in this paper. First, the working principle of the whole system is introduced. Secondly, the information process architecture of relative navigation and a very practical Kalman filter equation are established and the obtaining method of relative observed information is studied using the differential pseudo-range means. Finally, the simulation results show that the research method in this paper has the better performance, and all the wing planes can get continuous and smooth relative navigation information with highly precision.