The　oscillation　formation　at　the　beginning　of　the　holographic　recording　phase　in　two-center　holographic　storage　in　double-doped　LiNbO3:Fe:Cu　crystal　is　investigated.　After　pre-exposing　the　crystal　with　ultraviolet　(UV)　light　before　recording,　the　electron　distributions　in　the　deep　and　shallow　trap　centers　of　double-doped　crystals　are　in　a　dynamic　equilibrium　state.　At　the　beginning　phase　of　recording,　a　large　quantity　of　electrons　at　shallow　trap　centers　are　excited　by　introducing　two　red　beams　interference　in　the　crystal,　and　then　the　electron　distribution　transfers　to　another　equilibrium　distributions.　The　feasibility　to　use　the　decrease　of　electron　number　in　shallow　trap　centers　at　the　oscillation　phase　for　equal　time　exposure　and　then　realize　holographic　multiplexing　recording　with　equal　diffraction　efficiency　is　analyzed　theoretically.　The　multiplexing　of　15　holographic　gratings　of　equal　diffraction　efficiency　is　implemented　in　LiNbO3:Fe:Cu　crystals　with　100　s　equal　time　exposure.　The　results　show　that　it　is　feasible　to　conduct　a　small　scale　of　hologram　multiplexing　with　equal-time　exposure　during　the　oscillation　phase　of　the　recording.