With the rapid development of cloud computing technology, its security issues have become more and more obvious and received much attention in both industry and academia. High security risk is widespread in traditional cloud architecture. Hacking into a virtual machine destroys the availability of cloud services or resources. Un-Trusted cloud storage makes it more difficult to share or search users' private data. The risk of privacy leakage is caused by various outsourcing computation and application requirements. From the perspective of security and privacy preserving technologies in cloud computing, this paper first introduces related research progress of cloud virtualization security, cloud data security and cloud application security. In addition, it analyzes the characteristics and application scopes of typical schemes, and compares their different effectiveness on the security defense and privacy preserving. Finally, the paper discusses current limitations and possible directions for future research.