The　question　of　whether　the　opening　of　a　tunnel＇s　internal　ventilation　and　smoke　exhaust　system　will　affect　the　fire　extinguishing　abilities　of　the　automatic　water　spraying　system　after　a　fire　occurs　was　investigated.　The　fire　scene　in　a　well-ventilated　tunnel,　with　a　critical　wind　speed　for　a　20　MW　wood　pile　fire　and　oil　pool　fire　by　the　full-scale　burning　test　method,　was　examined.　The　influence　of　shelter　above　the　fire　source,　and　the　opening　time　sequence　of　ventilation　and　fire　extinguishing,　was　also　investigated.　Results　showed　that　ventilation　reduced　the　ceiling　temperature　in　the　tunnel,　improved　visibility,　and　improved　the　fire　extinguishing　efficiency　of　the　automatic　fire　extinguishing　system,　to　a　certain　extent.　For　the　solid　fire　with　top　shield,　the　ventilation　system　started　later　than　for　the　water-foam　spray　system.　This　increased　the　fire　locally　and　prolonged　extinguishing　time.　For　fires　in　vehicles　transporting　hydrocarbon-based　solid　goods,　the　ventilation　system　is　started　earlier,　or　simultaneously　with　the　fire　extinguishing　system,　to　get　better　fire　suppression　efficiency.　©　2019,　Editorial　Department　of　Journal　of　HEU.　All　right　reserved.