Abstract: Objectives: BDS-3 (BeiDou Global Navigation Satellite System) PPP-B2b supports real-time precise positioning services by broadcasting real-time precise correction message, but the convergence time remains relatively long. Low Earth Orbit (LEO) satellites can be used to augment positioning for rapid convergence due to the characteristic of high-speed movement. The integration of LEO augmentation with PPP-B2b is expected to achieve real-time and rapid precise positioning. Method: In this paper, we investigate the rapid precise positioning method using LEO augmentation for BDS-3 PPP-B2b, evaluate the accuracy of real-time orbit and clock product over 30days, and conduct a comparative verification through data analysis of BDS-3-only and GPS/BDS-3 dual system positioning performance with 1 and 2 low-orbit satellites. Results: The accuracies of the along-track, crosstrack, and radial components of the PPP-B2b satellite orbit are superior to 0.35, 0.30, and 0.10 m, respectively, and the clock offset accuracy is within 0.15 ns. The convergence time for the BDS-3-only can be reduced to 5.53 and 4.50 min with the addition of 1 and 2 LEO satellites, respectively, and the 3D positioning accuracy improves from 87.17 cm to 12.59 and 11.28 cm, respectively. For GPS/BDS-3 dual system, with the addition of 1 and 2 LEO satellites, convergence time can be shortened from 16.15 min to 4.03 and 3.54 min, respectively, which is shortened by 75% and 78%, respectively. And the 3D positioning accuracy improves by 32% and 33%, increasing from 10.18 cm to 6.89 and 6.83 cm, respectively. Conclusions: LEO satellites augmentation brings significant improvement to the positioning performance of PPP-B2b, showing the enormous potential for achieving real-time, rapid and precise positioning.