Abstract: The late Permian is an important transition period in geological history. The shale sedimentary environment in the study area during this period is reconstructed under frequent sea level changes, and the influence of sea level rise and fall on organic matter enrichment is discussed. The analysis of carbon isotopes, maceral components, major and trace elements shows that TOC in the Upper Permian shale ranges from 0.03% to 23.12%, with an average TOC content of 5.13%, and the organic matter type is type I to III, which is in the stage of over-mature evolution. The frequent sea level rise and fall in the study area lead to complex changes in the sedimentary environment: it is in a semi-humid - semi-arid climate, with anaerobic-oxygen-lean - anaerobic evolution process, the paleoproductivity has undergone low-high-low changes, and there are hydrothermal activities. The dominant factor of organic matter enrichment in the Late Permian was paleoproductivity, and there were 6 times of massive organic matter enrichment in the whole period. Frequent sea level rise and fall led to complex and diverse driving factors of paleoproductivity: When sea level rises, upwelling acts as a medium to transport nutrients brought by hydrothermal activities, resulting in the prosperity of productivity, while when sea level falls, terrigenous clastic input acts as the main material source to promote paleoproductivity.