Based on the application requirements of high-speed optical data multi-hop transmission in free-space optical communication network, and aiming at the problem that the signal quality of phase-modulated laser link after long-distance transmission in space degraded, the all-optical phase regeneration for binary phase shift keying modulated high-rate signal, based on the phase-sensitive four-wave mixing (FWM) effect in high nonlinear fiber (HNLF) was proposed. Numerical analysis with Matlab was carried out to find out the factors affecting the regeneration results. Then based on the OptiSystem simulation tool, an all-optical phase regeneration system for a 10 Gbit/s differential phase shift keying (DPSK) optical signal was constructed. Combining the link budget for geosynchronous (GEO) to optical ground station (OGS), system performance in three situations, namely back-to-back (B2B), phase-noised as well as noised-and-regenerated, were compared and analyzed. Simulation results and numerical analysis results show that compared with the system without regeneration after degradation, the bit-error-ratio (BER) of the noised-and-regenerated system improves nearly 4 orders of magnitude, while the output optical signal-to-noise-ratio (OSNR) increases nearly 3 dB. The results indicate that all-optical phase regeneration in free-space optical communication system can achieve all-optical phase regeneration of phase modulation signal. It can effectively promote the performance of spatial coherent laser communication system and can be used in the all-optical data relay of high speed free-space optical communication network relay nodes.