This study is designed to address the issues of group user authorization management and integrity verification for shared medical data. First, to prevent group users from overstepping their authority, authorization identifiers are introduced. Medical data owners use authorization identifiers to allocate different access rights to group users, according to user identities. The mathematical construction of authorization identifiers effectively ensures that it cannot be forged. Second, to record revoked users and deprive them of access rights, a revoked user list based on a skip list is introduced. As skip list can support fast lookup and insertion, the overhead of revoking a user is only O(logn). Afterward, the concrete process and mathematical design of shared data integrity verification are improved. Finally, the security analysis and simulation experiments prove the security and efficiency of the scheme.