In order to take full advantage of enterprises' infrastructure located in different systems, protect the company's core data and provide a unified secure operating interface and operating environment and avoid redeployment for each system, duplicate complex work of design, a better solution is building an enterprise private cloud. This paper analyzes the private cloud architecture and its advantages, such as topology, caching mechanism, load balancing strategy and storage pool design, through physical machine cluster technology and Xen virtualization technology designs Xen-based private cloud infrastructure, and provide users with a unified the simple structure interface.