Abstract: The rapid development of computer networks and the popularization of big data have promoted the further development of cloud computing. The cloud environment is an important platform for data interaction in the network and information age. It provides great convenience for the efficient data interaction of individuals, enterprises and countries, but it also poses new challenges for the security of cloud data. In this paper, we first present the existing cloud computing model, investigate and analyze the threats in cloud data security protection schemes. On this basis, a systematic analysis of the latest research results of cloud data security protection schemes at home and abroad is conducted, namely, access control, key agreement, secure data auditing and secure data sharing. Secondly, we conduct systematic research and propose solutions to the problems such as easy disclosure of user privacy during the access control process, difficulty in controlling overhead during key generation, low efficiency in dynamic operations during auditing, and difficulty in tracking malicious users during data sharing in existing cloud data security protection schemes. Finally, the current challenges and future research directions of cloud data security protection are discussed, with a view to promoting the establishment of a more complete cloud data protection system.