A　reduced-scale　temperature　model　was　used　to　simulate　Xiangshan　Tunnel　in　experiments　exploring　the　influence　of　vertical　ventilation　on　the　spread　of　smoke　in　tunnel　fires.　The　results　showed　that　the　ambient　temperature　and　vertical　ventilation　impacted　the　spread　of　smoke　in　a　tunnel.　A　lower　ambient　temperature　increased　the　speed　of　the　smoke　spread.　A　greater　longitudinal　velocity　ensured　that　the　flue　gas　spread　downstream　of　the　fire　source,　but　the　smoke　also　settled　faster.　Thus,　the　smoke　layer　could　be　destroyed,　and　the　turbulence　would　endanger　human　evacuation.　The　theoretical　and　measured　values　showed　satisfactory　agreement　for　the　critical　smoke　stratification　speed.　The　maximum　smoke　temperatures　near　the　tunnel　ceiling　with　different　horizontal　distances　from　the　fire　source　were　also　close　to　the　values　predicted　by　the　Alpert　formula.　The　test　results　indicated　that　ventilation　greatly　affected　the　temperature　inside　the　tunnel,　but　increasing　the　wind　speed　did　not　further　decrease　the　temperature.　Further　away　from　the　fire　source,　ventilation　had　little　effect　on　the　temperature.　Based　on　the　experimental　results,　suggestions　are　provided　for　the　management　department　to　control　the　longitudinal　velocity　and　perform　an　evacuation　in　the　event　of　a　tunnel　fire.