This　paper　takes　a　certain　typical　cross　transfer　station　of　Beijing　subway　as　the　study　object,　establishes　the　physical　and　mathematical　model　for　the　movement　of　the　fire　smoke,　adopts　a　computational　fluid　dynamics　method　to　simulate　the　dynamic　process　of　development　and　spreading　of　the　fire　smoke　when　fire　occurs　at　two　positions　in　the　transfer　station,　discusses　about　the　distribution　rules　of　the　temperature　field,　the　velocity　field,　the　visibility　and　so　on　which　reflect　the　flow　and　development　characteristics　and　further　provides　reference　for　making　the　smoke　control　and　exhaust　scheme　and　evacuation　scheme.　The　simulation　computation　shows　that　when　the　fire　occur　in　the　subway　transfer　station,　the　＇chimney　effect＇　is　more　obvious,　and　there　are　mutual　action　and　mutual　influence　for　the　temperature　field,　the　velocity　distribution　and　the　visibility　distribution　at　the　area　connected　with　the　transfer　station.　©　(2012)　Trans　Tech　Publications,　Switzerland.