After introduced the composition and function of Highway Network Communication System (HNCS), the HNCS model was established based on the fault tree analysis method. According to the provided impact assessment model, the influence of highway electromechanical system network reliability was analyzed, and subsequently the system reliability of HNCS was evaluated, This paper put forward the strategies to improving the network system reliability of highway electromechanical system, and providing the technical support for the maintenance work of highway network system electromechanical equipments.