Considering the problems such as centralized data storage and difficulty in data sharing in cloud computing environments, based on the combination of multiconditional proxy reencryption and attributebased proxy reencryption, a multiconditional attributebased threshold proxy reencryption scheme which supports multiple authorization conditions is proposed. The scheme supports finegrained access to ciphertext data under multiple keyword authorization conditions, and can limit the authorization conditions and scope of ciphertext sharing. Only when the attribute set meets the access structure in the ciphertext and the keywords are consistent with the keywords set in the ciphertext, users can access the data. This solution achieves finegrained access to ciphertext data under multiple keyword authorization conditions, supports flexible user revocation, prevents unauthorized decryption of ciphertext by conspirators, and protects the sensitive information of data owners. Through the provable security analysis, it is shown that under the general group model, the scheme can resist chosen plaintext attack; compared with other conditional proxy reencryption schemes, the functions it supports are more diverse.