The design of energy saving fuzzy control system for expressway tunnel lighting is discussed in this paper. Based on fuzzy control theory, an energy saving system for expressway tunnel lighting is designed. Firstly, the illumination intensity of the outside of expressway tunnel and the flow of tunnel traffic are measured on line. Then an adaptive control strategy is presented to adjust the lights in tunnel inlet and tunnel outlet, which can avoid “tunnel black hole effect” and “tunnel white hole effect”. Furthermore, a simple control method is proposed to adjust the lights inside tunnel. Finally, the practical running indicates that the proposed system meets the tunnel lighting design specification, and works stable. It can reduce 22% lighting energy compared with that of the same time interval, and has popularization value.