The　confidentiality　and　usability　of　sensitive　data　in　outsourcing　processes　are　particularly　important　in　open　systems.　When　the　user＇s　attribute　is　revoked　or　restored　in　the　CP-ABE　system,　the　flexibility　of　the　dynamic　change　of　the　corresponding　strategy　is　a　challenge.　In　the　paper,　we　presents　a　CP-ABE　access　control　scheme　which　supports　the　dynamic　changes　of　policy　attribute.　We　expanded　its　Access　Structure　Tree,　established　a　full　policy　access　control　mechanism　that　supports　the　minimum　shared　re-encryption　key　attribute　set,　and　realized　the　change　of　the　flexible　access　policy　in　the　scheme.