By jointly solving the two-center material equations and the coupled-wave equations, a dynamic model to study the nonvolatile hologram realized by the two-color recording scheme (UV-light for sensitizing and He-Ne laser for recording) in doubly doped LiNbO3 crystals is set up. The aim is to study the effects of the microscopic optical parameters of the deep and shallow doping centers on the saturation and fixed diffraction efficiencies. These parameters include the photo-excitation coefficients of deep and shallow centers for sensitizing-light, the photo-excitation coefficient of shallow center for recording light, and the electron recombination coefficients of deep and shallow centers. Numerical solutions show that, for the nonvolatile holographic storage in doubly doped LiNbO3 crystals, in order to obtain high fixed diffraction efficiency, one should select the shallow center with large electron recombination coefficient, with high photo-excitation coefficient for recording light and with low photo-excitation coefficient for sensitizing-light; and select the deep center with high photo-excitation coefficient for sensitizing-light and with optimal electron recombination coefficient.