Abstract: The Middle to Late Triassic period was a critical climatic transition phase in Earth's history. During this time, multiple global humid climate events exerted profound impacts on marine and terrestrial depositional environments, facilitating the development of both marine and lacustrine source rocks. This study focuses on the hydrocarbon source rocks of the seventh member of the Yanchang Formation (Chang 7 Member) in the southeastern Ordos Basin. Through elemental geochemical and molecular organic geochemical analyses, this study elucidates the coupling relationship between humid climatic events and organic matter enrichment in lacustrine settings. The results reveal that the lower – middle interval of Chang 7₃ submember (695–660 m in depth) is characterized by high total organic carbon content and good hydrocarbon generation potential. Chemical weathering indices indicate that the lower middle interval of Chang 7₃ submember was deposited under warm and humid climatic conditions, while other strata were deposited under relatively cold and dry conditions. By integrating global characteristics of Middle–Late Triassic humid events and the carbon isotope stratigraphies of the Chang 7 Member, this study demonstrates a correspondence between the lower – middle interval of the Chang 7₃ and the Ladinian–Carnian humid climate event. The findings suggest that, under the influence of humid climate events, enhanced terrestrial nutrient influxes stimulated primary productivity in the lake, and intensified water column stratification and bottom-water anoxia created favorable conditions for organic matter preservation, leading to the deposition of high-quality source rocks. Following the event, climate shifted to relatively cooler and drier climatic conditions, with reduced terrestrial input and decreased primary productivity, leading to lowered oxygen depletion in the water and less favorable conditions for organic matter preservation and enrichment. This study not only provides new insights for the reconstruction of paleoclimate and paleoenvironmental during the Middle to Late Triassic but also offers an important reference for understanding the mechanisms of organic matter enrichment during extreme climatic events in geological history.