The process of making dynamic light intensity gain equalizer includes the steps of: making glass substrates with conducting film and painting one 5-10 micron thick record layer of PDLC material; designing holographic optical path and making volume holographic reflecting grating on the record layer; designing different holographic optical paths, making volume holographic diffraction gratings on the record layer and making H-PDLC volume holographic grating elements with different diffraction characteristics; connecting one group of PDLC volume holographic gratings of different parameters serially to constitute adjustable filter; applying different electric fields to control the grating elements, and while the varying light power changes the gain of EDFA, controlling the electric fields to alter the diffraction efficiency of relevant wavebands to re-flat the gain. The gain equalizer has high wavelength selectivity, high control precision independent on polarization, low control voltage and other advantages.