In oil-rich Yongan area, the faults have not only controlled the forming of structure belt, but also played an important role in hydrocarbon migration and accumulation. Based on abundant seismic data and lithology materials, this paper analyzed the feature of major faults. In addition, by combining with fault activity rate analysis and fuzzy comprehensive sealing evaluation in different places of the main faults, the transporting capacity of the main faults in different places is analyzed and the hydrocarbon accumulation regularity is summarized. The results show that east section of Yong3 fault and Yong41 fault, whose activity matches well with the hydrocarbon generation and expulsion periods, but the good sealing property is against the migration of hydrocarbon. The west section of Yong3 fault and Yong41 fault, Yong67 fault which have long active time and match well with the hydrocarbon generation and expulsion periods,and the sealing is poor and making hydrocarbon migration possible, so it is the key regions of reservoir formation. Besides, the three parallel aligned main faults make the reservoir formed in step in the study area, and making the hydrocarbon distribution become shallow gradually from south to north.