In order to screen heterogeneity of sensor hardware and support rapid development of applications in context-awareness, the idea of middleware is widely adopted. In this paper, the middleware is proposed to support the application development of contextawareness under the new-type networks environment represented by wireless sensor networks. It applies the updated service-oriented and light-weight structure with excellent expansibility and efficiency in the running process. Additionally, the architecture of middleware mainly contains five layers and two crosslayer modules: hardware abstract, service registry, context model, reasoning and application presentation layers; energy management module and security module. During the process of context-awareness, the new method of awareness synchronization is designed to ensure the sensitivity to context switch. At the end of the paper, a healthcare scenario is used to validate the design methodology and demonstrate the supporting function of middleware.