Overlying formation pressure，fault dip angle and shale content are the significant parameters for fault sealing capacity evaluation，and the reliability of evaluation results depends on the accuracy quantification of these 3 parameters. In the research of fault sealing of the central-southern Liaoxi Uplift，it is found that the actual overburden density increases with the increase of compaction. Overburden density function was obtained by density logging and depth regression，and then it was integrated to calculate the overburden pressure. The fault dip angle changes with lithology and stress，and it was calculated by 3D seismic interpretation results and spatial stereo method. The overall trend of mud content was determined according to the seismic data，and then it was corrected by well logging gamma value to obtain the more accurate shale content in fault zone. The 3 parameters of No.1 Liaoxi Fault and its branched faults in the research area uplift were calculated accurately，and then their products were used as the fault sealing indexes. Combined with the analysis of differences in oil and gas distribution，it is found that the sealing capacity of the northern section of the study area is the best，followed by the southern section，and the central part is the worst. The lower limit values of fault sealing index are related to the physical properties of oil and gas，and the lower limit values of natural gas，normal oil and heavy oil are 9.34，8.31 and 6.12，respectively.