The invention discloses a light-shading automatic regulatory system for a highway tunnel exit and entrance, and belongs to the field of transportation. The light-shading automatic regulatory system comprises a light-shading shed and a control system, wherein the light-shading shed is arranged outside the tunnel exit and entrance, the control system is used for adjusting the light-shading degree of the light-shading shed, and the control system comprises an external signal acquisition unit, an AD conversion module, a control unit and a motor transmission system. By using the control system to conduct automatic light-shading control on the tunnel exit and entrance, and through the arrangement of the control unit, smooth transition of the ambient light when a driver drives in or out of the tunnel can be achieved under different external illumination intensities and different traffic flow speeds, thus the automatic adjustment of the light-shading degree of the light-shading shed in the tunnel exit and entrance can be achieved, and thus the occurrence rate of traffic accidents in the tunnel exit and entrance can be sharply reduced.