Abstract: A stratigraphic combination of carbonate rocks and gypsum rocks is developed in the Ordovician Majiagou Formation in the central-eastern Ordos Basin, with a thickness of nearly 1000 m and relatively large burial depth. The key issue restricting exploration is whether there is effective hydrocarbon supply and large-scale hydrocarbon accumulation in the Ordovician pre-salt strata, which is far away from the weathering crust. Based on research on the tectonic evolution of the Ordovician in the later sedimentary period, and the allocation relation between the Ordovician strata and the coal-bearing source rocks in the upper Paleozoic, it is considered that there is a hydrocarbon supply window for the Ordovician pre-salt strata in the areas adjacent to the paleo-uplift, which are in direct contact with the coal-bearing source rocks of the upper Paleozoic and are distributed on a large scale. The window zone was in a downdip structural position during the peak of hydrocarbon generation and expulsion. Favorable factors such as hydrocarbon generation and pressurization have provided migration force, which is conducive to the migration and accumulation of natural gas towards high positions. A good reservoir-cap assemblage is formed by continuous and stable lateral distribution of gypsum cap rocks and dolomite reservoirs. There is potential for large-scale hydrocarbon accumulation in the Ordovician pre-salt formations in the central-eastern part of the basin. The Wushenqi-Jingbian-Yan'an area is favorable for exploration and should receive more attention in the future.