A　three-dimensional　full　scale　geometry　model　was　established　by　Computational　Fluid　Dynamics　(CFD)　software　based　on　the　typical　Subway　Transfer　Station　(STS)　of　Beijing.　Taking　Navier-Stokes　equations　and　renormalization　group　(RNG)　k-epsilon　two-equation　turbulence　model　as　mathematical　model,　applying　numerical　method　simulates　air　distribution　of　ventilation　and　air-conditioning　system　in　subway　transfer　station.　The　result　shows　that　the　piston　wind　effect　is　obvious,　which　resulted　in　some　temperature　rised　on　waiting　train　zone.　Meanwhile,　it　has　a　significant　impact　on　air　distribution　of　up　and　down　platform　and　transfer　channels.　Despite　the　interaction　of　air　distribution　between　the　two　stations　of　subway　transfer　station　was　occurred,　the　distribution　of　temperature　and　velocity　field　are　relatively　uniform　and　comparative　satisfactory,　which　meet　the　requirements　of　transitory　comfort　for　passengers.　So,　the　ventilation　and　air-conditioning　system　are　rational　and　anticipant.　In　conclusion,　CFD　technology　can　provide　theoretic　reference　for　thermal　environment　design　and　optimize　ventilation　and　air　conditioning　design　of　subway　transfer　station.