With the advance of cloud computing technology, more economic benefits have been brought to users. While satisfying the needs of users, cloud computing brings its advantages-low costs, rapid deployment and flexible scale adjustment into full play. Increasing number of data is stored in all kinds of networks with more and more companies and people using cloud computing service, thus put severe challenge on usersÂ data security and availability. Under these circumstances, the study analyzed data security of users, and found out that data storage security attracts attentions both from private users and business users. The security challenges cloud computing has brought to us are how to prevent usersÂ data from leaking, how to guarantee users obtain data efficiently and accurately. It introduced the research status of secure data storage under the circumstance of cloud computing. Surveys showed that experts and scholars have attached great attention to data security under this circumstance. Strategies on secure data transmission and storage based on cloud computing, including encryption and decryption processing, were also introduces in this paper. To protect user data security, structure model has been built and secure data storage system under cloud computing has also been introduced.