According to the different types of operating systems and other reasons, the most intelligent terminal applications and services development need to be customized. It leads to a long development cycle, high cost, increased the repetitive labor and resources waste problem. In this paper, the authors introduce the research and development of internet of things application adapter middleware, which can be suitable for various intelligent terminal with different data sources. This paper research the system architecture and technical architecture of the middleware. The middleware uses the object-oriented thought, applying the MVC (Model View Control), Adapter, Singleton, and other design patterns. The intelligent terminal middleware can improve the application ability of different field of Internet of things as well as expand the access channel in the field of Internet of things.