In this paper, Ordovician stylolite-bearing marine carbonate rock samples in the eastern-middle part of the Ordos Basin were selected and analyzed. A series of analytical experiments such as observation of casting thin section and fluorescent thin section, TOC test, Rock-Eval pyrolysis, X-ray diffraction of whole rock, and scanning electron microscopy were conducted to analyze the effect of stylolites in carbonate rocks on organic matter enrichment and hydrocarbon migration. It is indicated in the study that the stylolites represent higher TOC content and better oil-bearing properties than that of the neighboring matrix; however, the two contain similar kerogen type. The stylolite contains a relatively higher content of clay, quartz, dolomite, pyrite, and black bitumen; but relatively lower content of calcite. The grains in the stylolite generally represent basal cementation and matrix supported features. The pore developmental degree, pore types, and pore developmental density are better than that of the matrix, favoring the migration of hydrocarbon. In general, the stylolite demonstrates a positive effect on the organic matter enrichment, hydrocarbon generation, and fluid in carbonate rock with low organic matter abundance.