Cloud computing is a complex network environment, and traditional applications use authorization and authentication based on a single security domain mode, it does not meet the requirements of cloud computing, cloud computing needs to establish cross-domain security access control policy. Based on the analysis of the challenges of data security and privacy protection in the cloud computing, this paper introduces the principle and function of the OAuth2.0 protocol, and points out the OAuth2.0 advantage of open license technology and its application in the cloud computing. Finally, through a cloud computing example, the implementation methods and development ideas had been discussed.