The invention provides a module for achieving interconnection between a CosiMate network and a DDS network and a design method thereof. According to the module for achieving the interconnection between the CosiMate-network and the DDS-network, a relay program module is arranged between the CosiMate network and the DDS network and includes three threads, the thread C is responsible for being in synchronization with the CosiMate network to carry out data sending and receiving, the thread A sends drive events to the DDS network according to data received by a synchronous thread, and the thread Bis responsible for monitoring data sent by the DDS network and sending the data to the CosiMate network through the synchronous thread; a multi-functional logic model, a avionic system model and a flight control system are in data communication through the DDS network, wherein the multi-functional logic model is established by adopting Rhapsody, and the avionic system model and the flight controlsystem are established by adopting C coding; the CosiMate network includes an electromechanical model and CosiMate middleware which is connected with the electromechanical model; on the basis of the CosiMate middleware, the interconnection among a power-supply electric system model, an environment control system and a hydraulic system model which are included in the electromechanical model is achieved. The module for achieving the interconnection between the CosiMate network and the DDS network and the design method thereof can achieve the interconnection between the DDS network and the CosiMate network.