Numerical　study　was　carried　out　to　analyze　the　effect　of　door　opening　scenario　on　the　smoke　propagation　in　metro　tunnel　fires.　The　smoke　back-layering　length,　critical　velocity,　and　temperature　distribution　were　studied　under　a　total　of　8　working　conditions.　Results　show　that　the　opening　of　emergency　exit　doors　could　result　in　a　shorter　smoke　back-layering　length　in　the　train　compartment.　In　such　conditions,　a　smaller　driving　force　was　needed　to　approach　the　critical　velocity.　On　the　other　hand,　the　high　temperature　area　of　the　tunnel　evacuation　platform　would　change　under　different　opening　scenarios.　The　research　result　could　be　used　as　a　deeper　understanding　of　the　smoke　propagation　of　metro　fire　and　a　reference　for　the　formulation　of　smoke　control.　　©　Published　under　licence　by　IOP　Publishing　Ltd.