A method for re-amplifying and re-shaping optical signal based on four-wave mixing effect (FWM) in fiber is proposed to realize optical signal 2R regeneration, and the working principles of this method are analyzed. An optical fiber transmission simulation system based on FWM effect to realize 2R regeneration of optical signal is designed. Simulation results show that, the 2R regeneration signal is good and the system Q value is up to 21.59, which verifies the feasibility of the proposed method. The wavelength and power of pump light are the main factors affecting FWM efficiency and regeneration performance. The optimal performance of the system is obtained when the pump wavelength and power is 1548nm and 40dBm, respectively.