For　the　problem　that　it　is　difficult　to　evaluate　overall　control　effects　when　timing　PID　controller　parameter,　this　paper　propose　an　evaluation　method　tuning　PID　controller　parameter　which　is　based　on　Fluent　and　computer　aided　engineering.　This　method　uses　Fluent　to　emulate　controlled　object,　and　Fluent　UDF　to　conduct　the　unsteady　closed-loop　control,　achieving　evaluation　for　PID　controller　parameter　tuning.　Taken　northern　platform　in　one　of　the　station　of　the　Line　5　in　Beijing　for　example,　the　results　show　that　the　method　can　be　effectively　evaluate　the　control　effects　in　different　control　parameters.