At　the　entrance　of　a　tunnel,　reflection　of　sunlight　from　the　surrounding　environment　and　a　lack　of　adequate　lighting　usually　cause　some　vision　problems.　The　purpose　of　this　study　is　to　optimize　the　lighting　environment　at　the　entrance　of　highway　tunnels.　Firstly,　based　on　a　highway　tunnel　in　Zhejiang　Province,　the　natural　illumination　intensity　in　different　seasons　and　climate　conditions　inside　and　outside　the　tunnel　entrance　was　analyzed　by　means　of　DIALux　simulation　software.　Then　the　variation　in　illumination　conditions　with　distance　at　the　entrance　of　the　tunnel　was　analyzed.　Finally,　based　on　the　results　above,　this　study　proposes　four　solutions　as　follows:　Setting　up　a　shading　shed,　auxiliary　lighting　facilities,　decelerating　reflective　markings,　and　an　adaptive　dimming　system.　©　2019　by　the　authors.　Licensee　MDPI,　Basel,　Switzerland.