The Upper Paleozoic in Linxing Middle Block is rich in coalbed methane, tight sandstone gas, shale gas and other resources. By testing the major elements and trace elements and clay mineral composition and desorbing gas of mudstone samples from different strata in Linxing Middle Block, we analyzed Changes in geochemical characteristics and paleo-salinity, paleoclimate and paleo-sedimentary water conditions in this area, as well as the relationship between depositional environment and formation gas content. The paleo-salinity value shows a trend of increasing gradually from the Benxi Formation to the Shanxi Formation. In Linxing Middle Block, from the Upper Carboniferous Benxi Formation to the Lower Permian Taiyuan Formation and Shanxi Formation, the paleo-salinity value decreases, and the sediments change from marine facies to In the transition of sea-land transitional facies, the paleoclimate showed a change from warm and humid to arid to warm and humid, and the sedimentary period showed a strong reducing water environment. The characteristics of the paleo-sedimentary environment show that the Taiyuan Formation with high paleo-salinity, an arid paleoclimate and a reduced water environment during deposition has the best gas content. Although the Benxi Formation has high paleo-salinity, its paleoclimatic characteristics show a warm and humid climate, and its gas content is not as good as that of the Taiyuan Formation. Therefore, in the paleo-sedimentary environment, the characteristics of paleoclimate are the factors that have the greatest influence on the gas-bearing properties of the formation.