We　present　a　new　method　of　realizing　the　spatial-identification　image　encryption　based　on　digital　holography　in　order　to　improve　the　encryption　degree　and　increase　encryption　freedom.　Both　the　object　beam　and　the　reference　beam　are　modulated　with　random　phase　respectively.　The　random　phase　displayed　on　the　spatial　light　modulator　(SLM)　in　the　reference　arm　is　being　refreshed　synchronously　when　the　aperture　is　scanning　over　the　original　image.　The　original　image　is　divided　into　many　subareas　by　the　scanning　aperture,　and　the　object　beam　from　each　subarea　interferes　with　a　reference　beam　with　unique　random　phase.　Therefore,　many　sub-holograms　are　captured　and　each　sub-hologram　is　encrypted　with　its　own　sub-key.　The　spatial　position　of　the　aperture　becomes　additional　secret　key　because　it　is　necessary　that　each　sub-key　should　match　with　each　encrypted　sub-hologram　for　obtaining　a　completely　decrypted　image.　This　method　greatly　improves　the　image　encryption　degree　and　guarantees　the　security　of　the　information.　The　whole　original　image　is　retrieved　by　superposition　of　all　decrypted　subareas.　The　encryption　and　decryption　are　demonstrated　by　simulations.