Due to user revocability, the new data manager needs to verify the integrity of the former data manager's management data stored in the cloud server, which is obviously inevitable in reality. In order to solve this issue, an efficient privacy-preserving public auditing scheme for cloud storage scheme was proposed. Firstly, in the proposed scheme based on unidirectional proxy re-signature, the proxy re-signature key was generated by the current data manager's private key and the former public key, which did not leak any information, to realize transferring of ownership data caused by the users revocability securely. Secondly, it was proved that the proposed scheme could protect any malicious cloud server from generating the forged response proof which could pass the verification to cheat the Third Party Auditor (TPA). Moreover, the random masking technique was employed to prevent the curious TPA from revealing the primitive data blocks. Compared with the Padna scheme, even though the proposed scheme adds the new functions but its communication overhead in the process of auditing and computational cost are also lower than Panda's.