:本文介绍了云计算应用的基本概况及云计算发展遇到的关键问题，基于Internet的云计算数据访问安全是云计算安全的中心。本文设计了基于MD5、SM2及SSF33算法和身份认证的PKI安全访问体系架构，基于此安全访问架构下的公开信道的数据访问安全得到了保证。-: This paper describes the application of cloud computing and cloud computing basic overview of the key issues encountered in the development, Internet-based cloud computing data access security is cloud computing security center. This article is designed based on MD5, SM2 and SSF33 algorithms and authentication of PKI security access system architecture, based on the security fr a mework of the public access channel data access security is guaranteed.