A numerical model for multi-wavelength operation of an erbium-doped fiber ring laser with frequency-shifted feedback was presented, which based on both the standard propagation and the rate equations of a homogeneous two-level medium. The similar model has been used for the analysis of EDFA. The numerical simulations with this model provided useful information of the spectral behavior as well as important parameter for device analysis and design. This model was used to study the origin of the suppression of the EDF's homogeneous broadening due to the presence of the frequency shifter. The model was demonstrated its validity by comparing the numerical solution with experimental results, which provided the useful tool for the EDFRL device research and development.