In　order　to　study　the　exhaust　effect　of　the　point　smoke　exhaust　system　in　V-shaped　urban　underground　tunnel　with　different　structures,　effects　of　the　slope　differences　on　both　sides　of　the　slope　changing　point　and　the　operating　mode　of　the　exhaust　vent　on　the　smoke　spread　distance,　temperature　at　the　height　of　2　m　above　the　road　and　the　ceiling　temperature　were　studied　by　the　numerical　method.　The　research　results　show　that　for　the　symmetric　V-shaped　tunnel,　smoke　can　be　controlled　in　the　required　range,　but　for　asymmetric　V-shaped　tunnel　with　the　slope　difference　on　both　sides,　smoke　cannot　be　easily　controlled,　ventilation　supply　is　needed　to　improve　the　smoke　exhaust　efficiency.　Point　smoke　exhaust　system　cannot　effectively　reduce　the　maximum　temperature　of　the　ceiling　above　the　fire.　When　the　fire　source　power　is　large,　for　the　symmetrical　V-shaped　tunnel　with　a　small　slope,　some　fire　prevention　measures　must　be　taken　to　protect　the　ceiling　partition.　For　the　asymmetric　V-shaped　tunnel,　two　exhaust　vents　opened　on　the　small　slope　side　and　four　opened　on　the　large　slope　side　are　suggested　for　the　occupant　safe　evacuation　in　tunnel.　　©　Published　under　licence　by　IOP　Publishing　Ltd.