Abstract: With the further exploration of Ordos Basin, the new areas in the periphery of the basin have gradually become the next key exploration targets. By studying the source and reservoir conditions of Yanchang Formation in the southern Tianhuan depression of Ordos Basin, and analyzing the correlation between crude oil and source rock, as well as hydrocarbon accumulation period and characteristics, this paper discusses the hydrocarbon enrichment characteristics and accumulation model of the study area. The research results show that the shale of the 7th oil layer of Yanchang Formation (Chang 7 oil layer)has a thickness of 5-20 m in Pingliang-Yanwu area, thinning to the northwest in Yinjiacheng-Xiaocha-Pengyang area. Shale in the study area has type Ⅱ₁ and Ⅱ₂ organic matter types, low maturity (average vitrinite reflectance of 0.65%), and the total organic carbon content (2.37%on average)and hydrocarbon generation capacity significantly lower than those of the corresponding strata in the central basin. The reservoirs in the study area are bounded by the mudstone of Chang 7 oil layer, which can be divided into two sets of accumulation assemblages, i.e., the assemblage of source in the upper and reservoir in the lower and vice versa. The main charging stages of reservoirs are in the Early Cretaceous period. The oil source in Pingliang-Yanwu area is mainly from the high-quality source rocks of Chang 7 oil layer in the central basin, and its reservoir types are mainly structural and structural-lithologic reservoirs, with the overall characteristics of multiple reservoirs distributed above and below the source, multiple channels transported by faults and sand bodies, and reservoir controlled by the combination of structure and lithology. Pingliang-Yanwu area has favorable conditions for hydrocarbon enrichment and accumulation. With the progress of 3D seismic and reservoir reconstruction technology, Pingliang-Yanwu area has great potential for oil and gas exploration, and is an important replacement area for increasing reserves and production in the western margin of Ordos Basin.