Deep shale gas from the Longmaxi Formation has been discovered in recent years in both Luzhou and Yuxi in southern Sichuan, and deep shale gas will become an important exploration direction for shale gas in China. The Hechuan Tongnan region is located in the gentle slope area of the ancient uplift in central Sichuan, adjacent to the western Chongqing and Luzhou regions. Drilling reveals active oil and gas display in the Silurian Longmaxi Formation, characterized by well leakage, overflow, gas invasion, and abnormal gas logging. The maximum total hydrocarbon content is 12.96–100%, and the total hydrocarbon gas content in the Tongshen A well is 100%. The drilling depth is greater than 4000m, but currently, there has been no breakthrough in deep shale gas in the research block. By conducting analysis such as thin section electron microscopy, surface area, whole rock analysis, organic carbon, and adsorption gas experiments, the shale facies and reservoir spatial types of the Longmaxi Formation were evaluated. Research has shown that there are 7 types of lithofacies developed in the study area, mainly including siliceous shale, clayey siliceous mixed shale, and clayey shale. Among them, siliceous lithofacies is favorable. Research suggests that the Longmaxi Formation in the study area has developed semi deep-water to deep-water continental shelf rich organic siliceous shale with good gas content. The shale as a whole has characteristics of high organic carbon, high gas content, high porosity, and high brittleness index. The research results provide effective data support for the evaluation of effective deep shale gas reservoirs and the selection of favorable shale gas areas in the future research area.