Cloud computing provides users with a dynamic resource allocation solution, which can deal with massive data according to user needs. It has good application for massive internet data storage and processing. However, the data security problem in cloud computing is the key to its sustainable development and application. This paper analyzes the data security factors in the cloud computing environment, and explores the data integrity protection, data sharing security protection and data storage carrier security protection in the cloud computing environment. MB-tree data structure is proposed to improve data integrity protection. The extended fuzzy identity encryption mechanism ensures the privacy protection of data interaction in the aspect of data sharing security protection. In the aspect of security protection of data storage carrier, a virtual machine trusted platform VTPM module is proposed to guarantee the migration of virtual machine in trust environment.