The total length of the Datianpo Tunnel is 2934 meters, with a total length of 1442 meters on the left, a maximum depth of 112 meters, a total length of 1492 meters on the right and a maximum depth of 120 meters. Datianpo Tunnel is a separate tunnel, which belongs to the low-mountain geomorphic area of structural corrosion and erosion. The topographic fluctuation is large. 750 sets of tunnel lights were reconstructed. SPARK’s upgraded simple but high-efficient LED tunnel lights were adopted, meanwhile the intermediate supplementary lights installation method is adopted too. The secondary optics made the tunnel free of zebra road phenomenon and greatly improved the lighting effect of the tunnel.