Abstract: An efficient fine-grained access control scheme is presented. The use of disjunctive normal form(DNF) instead of traditional AND/OR structure can optimize the access tree of CP-ABE algorithm and greatly reduce the recursive computation and cost in the process of encryption and decryption. The use of proxy re-encryption and attribute version numbers not only reduces the computational overhead of the data owner but also improves the efficiency of attribute revocation. Finally, the related analysis and simulation experiment results show that the new scheme is efficient.