SichuanBasinisatypicalsuperimposedbasin,whichexperiencedmulti-phasetectonicmovements,meanwhileSinian–Cambrianunderwentcomplexhydrocarbonaccumulationprocesses,causingexplorationdifficultiesinthepast60years.Basedonthemicroscopicevidenceoffluidinclusions,combinedwithbasin-modelling,thispaperdeterminesstagesandtimeofhydrocarbonaccumulation,reconstructsevolutionofformationpressureanddynamicprocessesofhydrocarbonaccumulationinSinianDengyingFormation-CambrianLongwangmiaoFormationofGaoshiti-Moxistructure.Threestagesofinclusionsaredetected,includingastageofyellow-yellowgreenfluorescentoilinclusions,astageofbluefluorescentoil-gasinclusionsandastageofnon-fluorescentgasinclusions,reflectingthestudyareahasexperiencedaseriesofcomplexhydrocarbonaccumulationprocesses,suchasformationofpaleo-oilreservoirs,crackingofcrudeoil,formationofpaleo-gasreservoirsandadjustmenttopresentgasreservoirs,whichoccurredduring219–188,192–146and168–0Marespectively.Duringtheperiodofcrudeoilcracking,DengyingFormation-LongwangmiaoFormationshowedweakoverpressuretooverpressurecharacteristics,thenafteradjustmentofpaleo-gasreservoirstopresentgasreservoirs,thepressureinDengyingFormationchangedintooverpressurebutfinallyreducedtonormalpressuresystem.However,duetoexcellentpreservationconditions,theoverpressurestrengthinLongwangmiaoFormationonlyslightlydecreasedandwasstillkepttothisday.
