Hydrocarbon source rocks are recognized as significant sources of oil and gas in China. The Carboniferous-Permian Taiyuan period is an important coal-forming stage in the North China Craton. During this period, a substantial amount of organic-rich rock strata was deposited, exhibiting considerable hydrocarbon-generation potential. The organic-rich rocks under the unminable thin coal seams of the Taiyuan Formation, which were taken from the geothermal drilling with a depth of 4 km, were selected as the research object. The methods of microscopic optics, X-ray diffraction(XRD), X-ray fluorescence(XRF), and inductively coupled plasma mass spectrometry(ICP-MS) were applied to analyze the petrological and geochemical characteristics of the samples. Based on these analyses, the paleo-sedimentary, paleo-climatic, and paleo-salinity characteristics during diagenesis were discussed, and the organic matter sedimentation and enrichment model for the research area was proposed. The results indicate that the rock types of the organic-rich rock strata are classified as carbonaceous shale, mudstone, and siltstone. The main mineral composition consists of kaolinite, dickite, illite, mica, and quartz, with a minor amount of dolomite, calcite, pyrite, and siderite. The total organic carbon(TOC) in the rock ranges from 2.66% to 52.3%, averaging 21.46%. The H/C(0.06 ~ 0.12) and O/C(0.13 ~ 0.93) of the carbonaceous shale suggest that the organic matter is classified as Ⅱ-Ⅲ. The average vitrinite reflectance is determined to be between 1.76% and 2.02%, indicating that the organic matter is classified as high maturity. The major elements of the whole rock are dominated by SiO₂ and Al₂O₃, Trace elements Li and Bi are observed to be enriched. Based on the analyses of chemical index of alteration (CIA), Sr/Cu, Sr/Ba, Th/U, V/(V + Ni), U_EF-Mo_EF(the discriminant parameters of redox environment), Ce_anom(Ce anomaly index), and Mo/TOC, it is inferred that these strata are formed in a warm and humid climate, a brackish, anoxic, and reducing environment. Under the combined effects of an adequate paleo-productive material base and favorable organic matter preservation conditions, organic matter is enriched and preserved, ultimately leading to the formation of source rocks. The research results are considered to have theoretical and practical significance for developing the source rocks within coal measures in the Taiyuan Formation and for revealing the mechanism of organic matter enrichment.