According　to　the　mechanism　of　grating　formation　in　photopolymers,　the　dark　enhancement　was　investigated　for　a　novel　photopolymer　by　using　the　method　of　mathematic　model　combine　with　experimental　measurements.　The　result　indicates　that　the　weaker　intensity　of　writing　light　resulted　in　more　dark　enhancement,　even　though　the　same　saturation　was　reached　for　diffraction　efficiency　with　different　writing　intensity.　In　order　to　exploit　this　effect　to　enhance　diffraction　efficiency,　experiments　of　non-continuous　holographic　exposure　were　designed　and　conducted,　The　diffusion　time　constant　of　the　material　was　obtained　to　be　21　s　by　fitting　the　experimental　data　of　dark　enhancement　with　theoretical　model.　Based　on　the　measured　diffusion　time　constant,　the　period　of　non-continuous　holographic　exposure　was　determined.　The　experimental　result　indicates　that　the　diffraction　efficiency　of　a　non-continuously　exposure　is　higher　than　that　of　continuously　one　in　the　same　recording　condition.