Relative navigation based on data link ranging is an important navigation method for formation tasks in the case ofsatellite rejection. The composition and working principle of the relative navigation system is introduced. Aiming at asynchronousTime of Arrival (TOA) measurement, lack of observability, and continuous divergence of inertial navigation errors, especially therelative positioning problem where the distance between members is close and the distance estimation error accounts for a largeproportion compared with the actual distance, the relative navigation algorithm architecture based on error accumulation correction isstudied, the filtering state and measurement equation are established, and the experimental verification in the field situation is carriedout. The research shows that the relative navigation algorithm studied in the paper has good performance for the relative navigationpositioning accuracy and stability in the case of close member spacing.