Multiple-image　encryption　by　spatial　information　prechoosing　and　cascaded　blocks　scrambling　is　proposed.　The　spatial　information　of　secret　multiple-image　is　pre-chosen　in　advance　to　effectively　reduce　the　capacity　burden　of　following　encryption　system.　It　is　conveniently　achieved　by　selecting　or　compressing　the　spatial　information　of　multiple　images　to　meet　practical　demands.　Spatially　pre-chosen　multiple　images　are　reformed　to　a　new　image.　Cascaded　double　random　phase　encoding　system　is　used　to　encrypt　the　new　image,　and　the　blocks　scrambling　is　operated　at　the　input　of　each　sub-encoding　system.　Two　main　advantages　are　obtained:　1.　Since　the　spatial　information　prechoosing　enables　the　whole　system　to　afford　much　larger　information　capacity,　the　effective　multiplexing　capacity　is　improved　greatly;　2.　The　combination　of　blocks　scrambling　and　cascaded　random　phase　encoding　not　only　ensure　the　much　higher　system　security,　but　also　save　the　key　space　and　easy　the　key　to　save　and　release　compared　with　the　methods　by　each　pixel　scrambling.　Computer　simulations　have　shown　the　effectiveness　of　this　method.