In IHEP, more large scientific facilities requests more computing resources. Management of large scale resources requests efficient and flexible system architecture. Virtual computing through cloud technical is an approach. IHEPCloud is a private LaaS cloud which supports multi-users and multi-projects to achieve virtual computing. In this paper, we describe the infrastructure of virtual computing cluster in IHEP and discuss the work we done. We also show the performance testing for BES job. IHEPCloud has been online since Nov 2014 and works well. The performance penalty is also acceptable.