Based on the comprehensive application of core，electron microscopy and geochemical and logging data，the salinization process of the lake basin was restored to establish different sedimentary sequence at different salinization stages in order to clarify the relationship between saline environmental deposition and shale oil-gas. The properties of sedimentary rocks in different saline environments were studied such as hydrocarbon-generating ability，reservoir property，oil bearing property，mobility and so on. The results show that the paleosalinity of the upper of the fourth member of Shahejie Formation is higher than that of the lower of the third member of Shahejie Formation in Jiyang depression in the whole，but the salinization evolution is different in different sags. Salinity variation controls evolution sequence of lithology. Gypsum rock，Glauber’s salt，gypsum mudstone and dolomite lithology deposited in sequence in hypersaline water phase；limestone，argillaceous limestone/lime mudstone deposited in sequence in salt water phase，forming lime and organic matter laminae；argillaceous limestone/lime mudstone-calcareous mudstone/shale deposited in sequence in brackish water phase. Among them，the laminated shale formed in the salt water phase has strong hydrocarbon-generating ability，superior reservoir quality，high oil content and good fluid mobility，which is considered as the most favorable for the enrichment of oil and gas.