Considering of the problems of poor quality of power supply,voltage fluctuations and no automatic adjustment of light in the mountain highway tunnel,an adaptive energy-efficient system has been designed.In this system,the main transformer and terminal equipment use smart two linkage regulator,and an adaptive technology inside cave,light regulation,power factor automatic compensation techniques are also used to meet tunnel lighting design specifications.By this system,the high operating costs and tunnel safety can be solved well,and the energy saving can be achieved too.