Photorefractive properties of Zn:Fe:LiNbO3 crystals were compared with Fe:LiNbO3 crystals. We described the photoconduction and diffraction efficiency as a function of incident light intensity. The self-erasing of recording process in the Zn:Fe:LiNbO3 crystal is observed. We found that the diffraction efficiency of the crystal increased to a saturation value and then decreased as recording time increases. The phenomena were explained by the double-carrier four-trap model. A suit able exposure schedule is chosen to realize the angle-multiplexed volume holographic storage. We have stored 30 images in the same volume of the crystal.