In government policy guidance, cloud computing has become a new mainstream of ICT industry. In addition enhancing government efficiency, cloud computing can assist in the development of othe rindu stries, and migrate business on to cloud. It can also provide innovative services and business models. However, the authors found that policies to promote cloud computing in domestic information systems are hindered by high costs, inappropriate assessment methods and alack of bridging mechanisms for migrating information services on to cloud. It caused planning and building a cloud is not as expected. This paper based on the knowledge contribution architecture aims to propose a mechanism for cloud service bridge platform which could reduce the cost of the cloud migration and provide business opportunity channels.