The　urban　utility　tunnel　needs　efficient　ventilation　systems,　which　contributes　to　maintain　air　quality　in　the　utility　tunnel.　In　order　to　improve　ventilation　performance,　the　jet　fans　were　used　in　the　utility　tunnel.　Fluent　14.0　and　k-c　turbulence　model　were　applied　to　research　the　ventilation　performance　with　jet　fan　with　a　deflected　angle.　Results　showed　that　the　air　velocity　is　higher　in　the　upstream　of　fire　source　than　in　downstream　fire　source.　Typically,　the　deflected　angle　of　jet　fan　has　a　certain　effect　on　the　velocity　and　temperature　distribution　of　air　in　utility　tunnel.　The　optimal　deflected　angle　of　jet　fans　was　gamma　=　12　degrees　near　the　fire　source.