Taking the source rock samples of the Yanchang Formation in the southern Ordos Basin as the research objects, this study systematically investigates the geochemical characteristics of aromatic hydrocarbons, comprehensively identifies the source material composition and sedimentary environment, verifies the applicability of aromatic series maturity evaluation parameters in this region, and deeply discusses the application of aromatic hydrocarbon parameters in oil-source correlation and oil-gas migration tracing. The source rocks are predominantly composed of bicyclic and tricyclic aromatic hydrocarbons, while the relative abundances of tetracyclic and pentacyclic aromatic hydrocarbons are comparatively low. Meanwhile, trace fractions of polycyclic aromatic hydrocarbons (PAHs) including benzofluoranthene (Bflas), benzo[e]pyrene (Be Py), and retene (Ret) have been identified. The aromatic hydrocarbon parameter analysis indicates that the source rocks of the Yanchang Formation are generally mature thermal evolution stage, formed in a weakly oxidized-reduced environment, with sedimentation dominated by freshwater and brackish water. The source material primarily originates from lower aquatic organisms, with some contributions from higher plants. The source comparison results show that the crude oil mainly comes from the Chang 7 oil shale, and the migration direction of hydrocarbons in the Zhenjing area is from northwest to southeast. The results of this study provide geochemical reference for the study of the oil and gas accumulation law and further guidance for the exploration of the Mesozoic oil and gas.