Abstract: A large number of mines in southern Ordos Basin have coal-oil-gas symbiosis, and the crude oil leaking from the top and bottom of the coal mining process has brought great security risks to the coal mining, so it is necessary to further identify the source and space-time evolution of the crude oil. Yan’an Formation in Lucun mining area in the southern basin was selected as the research object. Samples of coal measure source rocks and working face crude oil were systematically collected, and organic carbon isotope and gas chromatography-mass spectrometry were conducted to analyze the carbon isotope and biomarker characteristics of source rocks and crude oil, and the source of Yan’an Formation crude oil in the mining area was explored. By identifying fault system in the mining area, formation time of the fault is discussed, combined with characteristics of regional stress field, temporal and spatial evolution of the oil leakage in Yan’an Formation coal mine in southern Ordos Basin is comprehensively revealed. The results show that: Crude oil in Yan’an Formation coal mine comes from lower Triassic Yanchang 7 source rock; NE-trending large fault developed in the mining area is a class II fault, which was formed by the tectonic stress of Indosinian period and then reformed by Yanshan and Himalayan tectonic movements. This fault provides the main channel for the migration of crude oil from Yanchang Formation to Yan’an Formation; Small EW trending fault developed in the mine is mainly controlled by NWW-SEE horizontal compressive stress in the middle and Late Yanshan period, and EW trending joint is mainly controlled by NNW-SSW trending stress in Mountain Age, both of which are the main paths of crude oil escape in the coal mining process of Yan’an Formation. In Early Cretaceous, source rock of Chang 7 Yanchang began to generate a large amount of hydrocarbon, and the formed crude oil migrated to Yan’an Formation along NE trending large fault, and finally flowed into the mine through EW trending small fault and joint. The research results can provide theoretical guidance for the prevention and control of crude oil leakage and safe exploitation in coal-oil-gas symbiotic mine.