With the development of IoT and cloud computing technologies, a kind of service-oriented manufacturing mode, cloud manufacturing, has arisen in recent years. Cloud manufacturing is developed based on the core technologies of cloud computing, but it is a service oriented manufacturing models. The core idea of cloud manufacturing is to uniform the resources related to the whole products life cycle into a manufacturing resources pool to provide real-time services as required. This paper starts from the seven layer architecture of cloud manufacturing. Then the key technologies of cloud manufacturing is introduced, such as resource encapsulation, resource matching scheduling based on database, task decomposition based on the historical statistics and virtualization technology. Lastly, we propose the cloud manufacturing prototype and its main applications.