The steady-state nonvolatile two-step, two-color holographic recording performance for both the congruent and the near-stoichiometric LiNbO_3:Fe was studied theoretically based on the two-center model. It is shown that the nonvolatile two-step, two-color holography performance in the near-stoichiometric LiNbO_3:Fe is much better than that in the congruent LiNbO_3:Fe within the intensity range reachable by the continuous-wave lights. In addition, it is shown that a light-induced space charge field of the order of 10~6 V/m is achievable in both the near-stoichiometric and the congruent LiNbO_3:Fe with high intensities.