The scheme of using the all-optical 2R re-amplification, re-shaping regenerator based on nonlinear optical loop mirror to amplify and shape the differential phase-shift keying (DPSK) signals among satellites is proposed. The principle of the regenerator is deduced theoretically, the restrictive condition of amplifying and shaping a signal is given, the input and output characteristics of the power and phase of regenerator are investigated by simulation, and the effect of coupling coefficient of coupler on the power characteristic is analyzed. The result shows that the 2R regenerator can significantly promote the performance of DPSK modulation/self-heterodyne detection system and the bit error rate decreases nearly two orders of magnitude compared with that without the regenerator.