In view of the problem of light efficiency utilization in low altitude illumination in tunnels, it is proposed in this paper to improve the lighting benefits by optimizing the light configuration. Combinational analysis of such parameters as light height, elevation angle and spacing in low altitude illumination is performed in this research by Dialux optical simulation software. The average road surface luminance, overall uniformity of road surface luminance and longitudinal uniformity of road surface luminance are taken as key evaluation indicators. The study shows that the optimal height, elevation angle and spacing of low altitude illumination are 3 meters, 40° and 1 meter respectively. The overall uniformity of road surface luminance of low altitude illumination can reach 0.97, the longitudinal uniformity of road surface luminance can reach up to 1.0. The luminous flux per meter is equal in the longitudinal direction of the tunnel. The average road surface luminance is affected by the light arrangement spacing to a very small extent, and the longitudinal uniformity of road surface luminance is affected by the height and elevation angle of the light very slightly.