For analyzing PPP-B2b actual service performance, PPP-B2b data and International GNSS(global navigation satellite system)service data for a period of 30 days as well as offshore shipborne dynamic data on 16 December 2021 were used for evaluating orbit and clock offset accuracy and testing real-time PPP(precise point positioning)positioning performance. And compared with the corresponding results of CNT—archived products of CNES(centre national d′etudes spatiales,CNES). Results show that the radial accuracy of BDS-3 (BeiDou navigation satellite system phase Ⅲ) and GPS (global positioning system) track of PPP-B2b service are 0.07 m and 0.089 m respectively, which are below CNT 0.041 m and 0.025 m. The clock offset accuracy of BDS-3 is 0.029 m, close to GPS clock offset, better than 0.057m of CNES product accuracy. In the static positioning test based on PPP-B2b, BDS and BDS-3+GPS average convergence time is less than 20 minutes, better than that of GPS, and the convergence accuracy is higher than GPS. In the dynamic test, the RMS value of BDS-3 and BDS-3+GPS in the NEU(north, east and up)directions are better than 11 cm, GPS is better than 26 cm. In offshore positioning testing, the RMS value of BDS-3+GPS of PPP-B2b in the NEU directions are 0.028 m, 0.074 m, 0.081 m, and the convergence time is 12.4 min.