The new technology-photoetching of making hologram with comput ar program to control was advanced in this paper. Its principlewas briefly introduced.the factor that effects the visaal angle and diffraction angle of this kind of hologramwas studied. The functions relations about visual angle or diffraction angle andreference-object angle and wavelength of reconstruclion light were proved. Theory foundation were provided for realizing thedevelopments andcolor encoding of this kind of hologram.