Abstract: Considering the validity evaluation of tunnel electro-mechanical systems, this paper studies the functions of the electro-mechanical system of a highway tunnel and the relationship among its devices. Based on a structural division of this system and the consideration of various influential factors, a model for the validity evaluation of the device, subsystem and integrated system was established through hierarchical data processing under the decision tree method and weight determination of each level evaluation factor under the expert method. A systematic evaluation method is proposed considering the interaction between the system′s hardware device and its software function as well the system′s objective state and actual efficiency, which has been verified by practices.