To clarify the distribution and evolution patterns of gas and water in tight sandstone gas reservoirs of the Shaximiao Formation in the Central Sichuan Basin, the sources of formation water, the main controlling factors of gas-water distribution, and the genetic evolution were systematically investigated using data from formation water chemistry analysis, core analysis, seismic surveys, well logging, and gas testing. The results indicate that the formation water in the first member of the Shaximiao Formation primarily consists of paleo-depositional water with a high proportion of bound water. Macroscopically, the gas-water distribution is controlled by the coupling relationship between source rocks and faults, paleo-and present structures, and reservoir heterogeneity. The genetic evolution types of gas-water distribution are classified into structure-physical property jointly controlled type and physical property primarily controlled type. During the accumulation period, natural gas preferentially migrated to structural highs configured by fault-sand coupling. Tight reservoirs with early cementation had low gas charging degrees and could be vertically adjusted via internal faults within the Shaximiao Formation. Physical property barriers formed by late cementation not only preserved early charged gas reservoirs but also acted as barriers for late charging. Based on structural changes, the fault-sand coupling relationship altered, leading to redistribution of gas and water within the reservoir, which was primarily controlled by reservoir heterogeneity. Consequently, gas layers, gas-water layers, and water layers coexist within the same channel.