The invention discloses a hybrid cloud computing system based on a cloud bus and a realization method of the hybrid cloud computing system. The system is based on a local private cloud, one or more public clouds are integrated, the internal constitution of the local private cloud is consistent with that of the public cloud, both the internal constitution of the local private cloud and the internal constitution of the public cloud comprise an infrastructure, a virtualization layer, a cloud platform layer, a cloud bus layer, a cloud application layer, a management center and a storage center, wherein the hardware resources on a bottom layer are grouped into a virtual cluster through the infrastructure and the virtualization layer so as to provide different virtual resources to the superior layer; the cloud platform is used for operating a web application program or a service and utilizing an open interface to carry out the secondary development and application integration; and the cloud bus layer is used for managing and monitoring various services on the cloud platform layer and is a hub for connecting the cloud application layer and the cloud platform layer, and the cloud bus layer is established on the basis of SOA (service oriented architecture) concept and comprises a control bus, a plurality of node buses and an adapter. Due to the adoption of the hybrid cloud computing system, the migration of the existing IT (internet) environment of an enterprise to a cloud computing environment can be accelerated, the investment can be reduced, and the resource can be adequately utilized.