Aiming at the characteristics of distributed satellites system that the information exchanging and wavelength conversion are frequent but the payload is limited, a wavelength conversion scheme based on the self-phase modulation (SPM) and the four-wave mixing (FWM) is put forward, which can substitute several pump lasers in case of multiple wavelength channels. By utilizing the SPM in high nonlinear fiber to broaden the spectrum of initial signal, a pre-conversion signal is obtained as the pump light for wavelength conversion through an offset filtering. Then the wavelength conversion is realized based on the FWM in semiconductor optical amplifier. The principle of the scheme is deduced theoretically, and the relationship between conversion properties and structural parameters is analyzed. The simulation results show that the scheme can improve the quality of signal to some extent when completing a wavelength conversion, the Q factor improvement can be of 3 dB at most, while the conversion efficiency can reach to 20 dB.