Abstract: We study PPP-AR rapid ambiguity re-convergence in the case of short-term loss or disruption of observation data, offer a reasonable extrapolation time threshold for using augmentation information, demonstrate the reliability improvement of existing URTK services when using this method, and design a corresponding real-time testing scheme to verify its availability. The results show that, augmentation information can be extrapolated for at least 30s, and that the PPP-AR rapid ambiguity re-convergence method can improve the reliability of URTK service for control center and rovers even in poor observation conditions. Rovers can independently realize ambiguity rapid re-convergence without the support of regional URTK augmentation service, which will reduce the real-time data communication burden between rovers and control center significantly.