Indoor　air　quality　of　a　public　transport　interchange　station　in　a　comprehensive　transit　hub　has　been　investigated　by　experimental　studied　and　numerical　simulation.　Carbon　monoxide　was　selected　as　the　main　pollutant　for　description　of　air　quality.　Ventilation　systems,　bus　traffic　and　passenger　flow　have　been　get　by　on-site　measurement.　Large　eddy　simulation　technology　has　been　applied　to　analyze　indoor　air　quality　of　public　transport　interchange　station.　The　boundary　conditions　are　determined　according　to　the　measured　date.　The　distributions　of　carbon　monoxide　at　heights　of　0.8m　and　1.6m　under　different　time　periods　and　operating　conditions　of　public　transport　interchange　station　are　calculated.　Time　periods　include　the　peak　hour　and　trough　hour　in　this　study.　Results　show　that　carbon　monoxide　concentration　in　peak　hour　is　about　twice　than　that　in　trough　hour　in　most　area　except　the　rear　area　of　the　vehicle.　Air　quality　would　reach　the　harmful　degree　in　period　between　5min　to　10min　if　the　ventilation　system　is　not　operating.　The　ventilation　system　should　be　operated　during　the　peak　hour　and　intermittent　operation　mode　can　be　adopted　during　trough　hour　in　order　to　meet　the　requirement　of　air　quality　standards.