Abstract: Information fusion is one of the key technologies in modem avionics system. Focusing on the characteristics of airbome sensors, this paper describes the design of an information fusion system, gives the implementation of a distributed fusion system. Firstly, the main functions and configuration of the system is described, which is divided into two parts and decomposed to modules. Secondly, the functional design of each module is given. In addition, the algorithm and the implementation of the key modules are analyzed. At last, the software implementation of the system which verified the system effectiveness and practicality is introduced.