A test campaign for carrier phase timing was conducted on the BDS/GNSS Open Testing Platform (BOTP), which was established by the National Time Service Center, Chinese Academy of Sciences (NTSC, CAS), using communication satellites in geosynchronous orbit. Its purpose was a navigation technology experiment and verification platform for BDS and GNSS. The system architecture of BOTP, a novel navigation system independent of GNSS, is similar to that of traditional GNSS, with the main difference being that the communication satellite transponder without an onboard atomic clock is used as the navigation satellite. Moreover, the navigation signal generated at the ground navigation station is transmitted to the communication satellite via a large-diameter antenna and is transparently retransferred by the satellite transponder to users. BOTP uses a high-performance stable ground atomic clock group instead of an onboard satellite atomic clock, and the navigation signals work in the C-band. Based on the various merits of BOTP, a novel timing method with a single communication satellite is proposed, and the results of a performance verification test campaign conducted by NTSC in Xi’an, Beijing and Sanya during June 2020 are described. The statistics show that (1) the standard deviations of the carrier phase timing are 0.061 ns, 0.556 and 0.828 ns at Xi’an, Beijing and Sanya, respectively, and (2) the corresponding 95% confidence intervals of the carrier phase timing are 0.114 ns, 1.259 ns and 1.695 ns. These results reflect the ability and potential application of BOTP for high-precision, real-time timing based on the carrier phase.