In order to study the distribution characteristics of oil and gas at faults above mudstone caprock at different brittle-plastic evolution stages in oil and gas bearing basins.Methods: Based on the study of the verticalsealing mechanism and influencing factors of faults in the mudstone cap at different brittle-plastic evolution stages, the vertical sealing of the faults in the mudstone cap in the brittle evolution stage was determined by the paleofault thickness of the mudstone cover in the brittle evolution stage and the maximum fault thickness required for the segmented growth of the fault in the brittle mudstone cover in the study area. The vertical containment of the faults in the mudstone cap at different brittle and plastic evolution stages was determined by the continuous distribution index of the paleomustone plastic deformation zone in the fault zone in the brittle plastic and plastic evolution stages and the maximum continuous distribution index of the continuous distribution of the mudstone plastic deformation zone in the fault zone in the fault zone in the study area.Results: The results show that Gangdong fault in mudstone caprock of the Middle Submember, 1st Member, Shahejie Formation（Es1Z）—Dongying Formation（Ed）, Oligocene is vertically sealed at L2903—L2213 and L2693—L2813. The vertical direction of the survey line L2213—L2633 is not sealed, Gangdong fault in mudstone caprock of the Es1Z in brittle plastic evolution stage of the Minghuazhen Formation（Nm）, Pliocene is sealed vertically at L2093—L2273 and L2693—L2813, but not sealed vertically at L2333—L2633, which is favorable for hydrocarbon accumulation in the Ed, Oligocene. This is consistent with the fact that oil and gas have been discovered in the 3rd Member, Dongying Formation（Ed3）of the Gangdong fault and are mainly distributed at the survey line L2324—L2704.Conclusion: The method is feasible to identify the vertical sealing properties of faults in the mudstone caprock at different brittle—plastic evolution stages.