The Chang 8 reservoir of Yanchang Formation in the southern Ordos Basin is a lithologic oil reservoir, and there are differences in the exploration results and accumulation processes in the Fuxian area in the east and Qingyang area in the west. The characteristics and age of accumulation were studied, and the differences in the migration and accumulation patterns of Fuxian and Qingyang in different periods were summarized. The results show that: (1) Delta front sedimentary facies and braided river delta sedimentary facies are developed in Fuxian area and Qingyang area respectively. The sedimentary scale in Qingyang area is smaller than that in Fuxian area. (2) Due to the influence of sedimentation and diagenesis, the reservoir physical property in Qingyang area is worse than that in Fuxian area; (3) Fuxian area experienced two periods of hydrocarbon charging, the first period of hydrocarbon charging is late Jurassic-Early Cretaceous, the second period of hydrocarbon charging is middle Early Cretaceous, Qingyang area mainly experienced the first period of hydrocarbon charging, and the accumulation time is middle early Cretaceous. (4) There are differences in migration and accumulation between east and west: in the Late Jurassic, Chang 9 in Fuxian area as the main source of hydrocarbon supply. Chang 9 hydrocarbon migration along to the chang 8 reservoir sand body, at the same time can also be used in its internal for the lateral migration of long distance, but the hydrocarbon generation intensity of the Chang 9 source rock in Qingyang area was not strong at this time, and only a small amount of hydrocarbon entered the Chang 8 reservoir along the sand body, and the accumulation combination was lower generation and upper storage; in the Early Cretaceous, tectonic activity was strong in Qingyang area, Chang 7 and Chang 9 are the main sources of hydrocarbon supply, and a large amount of hydrocarbon was charged along the fault zone. The hydrocarbon accumulation assemblages ware lower generation - upper storage and upper generation - lower storage. However, the Chang 7 source rock in Fuxian area was hydrocarbon generation at this time, but the hydrocarbon charging was weaker than that in Qingyang area because the fault zone was not developed. The difference in accumulation between the east and west of Chang 8 reservoir of Yanchang Formation in the southern Ordos Basin are clarified, and the hydrocarbon migration and accumulation model are summarized. The research results provide an important basis for guiding petroleum exploration and deployment in the basin.