Message middleware is an important branch of middleware, it provides the development of distributed application system with an asynchronous, pine for programming architecture, the consistent thought and the development trend of modern software technology, which is widely used in industry in the enterprise application integration and distributed computing. Message bus message middleware is a kind of simple implementation, but with its unique advantages for a wide variety of distributed applications development injected with strong power, greatly promote the development of application system integration. This paper is mainly focusing on the key issues involved in the middleware, message bus, and concurrency model for further research.