The　most　serious　fire　scene　in　a　subway　system　is　that　a　train　catching　on　fire　has　to　stop　in　the　tunnel.　The　objective　of　this　paper　is　to　discuss　safety　evacuation　of　this　scenario.　A　subway　tunnel　in　Beijing　was　selecting　as　research　object,　and　adopting　numerical　simulation　methods　to　analyze　smoke　propagation　in　the　tunnel　and　train　carriage.　In　addition,　the　influence　of　train　carriage　door　opening　on　the　smoke　spread　was　studied　in　the　double　narrow　space　formed　by　the　carriage　and　tunnel.　Results　show　that　the　opening　method　of　door　would　affect　the　smoke　spreading　path,　and　the　range　of　high　temperature　area.　For　a　fire　occurred　in　train　carriage,　opening　of　the　end　door　of　train　can　effectively　enhance　diffusion　of　smoke　into　the　tunnel.　This　research　is　not　only　helpful　to　guide　the　cabin　crew　to　evacuate　efficiently　and　orderly,　but　also　provide　guidance　for　the　planning　of　subway　tunnels.　©　2023　Institute　of　Physics　Publishing.　All　rights　reserved.