Abstract: Inthispaper,low-sulfurcrudeoil,high-sulfurcrudeoilandheavynaphthaoilwereselected tocarryoutfreecombustionexperimentwithdifferentcombustionareasinoutdooropenspace,andthe experimentaldataofcombustionrate,flametemperatureandheatradiationfluxatmeasuringpoints wereobtained.Inaddition,FDSwasusedtoestablishafull-sizemodeltoobtainthesimulationresults offlametemperatureandheatradiationfluxatmeasuringpoints.Theresultsshowthat:(1)Bothlowsulfurcrudeoilandhigh-sulfurcrudeoilhavethreecombustionstages.Thecombustionrateincreases almostinalineartrendintheinitialdevelopmentstageofcombustion.Thestablecombustionstageis notobvious,andtherearenotmanyobviousstablecombustionstages.Heavynaphthashowsboiling combustionphase.(2)Thetemperatureatthecenteroftheoilpanfirstincreasesandthendecreases withtheincreaseoftheheight,whilethetemperatureoutsidetheplumedecreaseswiththeincreaseof theheight,andthisdownwardtrendisfirstsharpandthenslow.Inthecontinuousflamearea,thehigh temperatureconcentrationtendstobestable,andintheintermittentflameareaandbuoyancyplume area,thetemperaturedispersiondegreeislarger.(3)Bycustomizingthecombustionratecurveinto FDS,accurate simulation of heat radiation flux received at the measuring point can be achieved.Whentheflameradiationfluxinthecylindricalmodelisdividedintotheluminousregion atthebottomandtheplumeatthetop,thehigherthepowerofthefiresource,thecloserthecalculatedvalueistothemeasuredvalue.Forthehigh-poweroilpoolfire,thecriticalcurveof“safety distance-time” canbedeterminedtoobtainthetimethatpeoplecanbeexposedatdifferentlocationsfromthefiresource.