Recent exploration has revealed the coexistence of coalbed methane (CBM), shale gas, and tight sandstone gas within the coal-bearing strata of the Paleozoic marine–continental transitional sedimentary environment in the Qinshui Basin, China. These three unconventional gas resources are exploration targets within coal seams, but current research primarily focuses on CBM. Hence, this study integrated investigation into the characteristics of CBM, shale gas, and tight gas reservoirs using core samples, logging data, and laboratory tests from Carboniferous–Permian strata in the southern Qinshui Basin. It clarifies the formation and evolution of coal measures gas; establishes a symbiotic combination model of CBM, tight gas, and shale gas; and discusses the coexistence mechanism of coal measures gas and the geological factors affecting symbiotic enrichment. Within the study area, source rocks, primarily composed of coal seams and organic-rich shales, are widespread and highly developed, serving not only as source rocks, but also as reservoirs with exceptionally low porosity and permeability. Interbedded sandstone forms tight reservoirs alongside coal and shales, with short migration distances conducive to free gas charging. Following the sedimentation of upper Carboniferous Taiyuan Formation–lower Permian Shanxi Formation (C₃^t-P₁^s) coal-bearing strata, two main gas generation episodes and one continuous gas expulsion process occurred, resulting in independent CBM, tight gas, and shale gas reservoirs. Due to the intricate relationship between source rock and reservoir configuration, tectonic uplift, and the influence of natural fractures, the three kinds of gas (CBM, tight gas, and shale gas) can coexist in various combinations. Gas migration and accumulation are influenced by variations in strata temperature and pressure due to changes in coal seam burial depth, leading to dynamic exchange equilibrium between different gas-bearing systems. Moreover, tectonic uplift has created fracture systems in tight reservoirs, facilitating gas migration and accumulation. Considering the relative positioning of thin coal seams, nearby cap rocks, and gas-bearing systems, the CBM symbiotic combination model can be categorized into three types: (1) a combination of sandstone, shale, and one or multiple coal seams form a double-source and three-reservoir gas reservoir; (2) two sets of shale or a single set of coal seams interleaved create a double-source and double-reservoir gas reservoir; and (3) the development of shale or coal seams results in a single-source and double-reservoir gas reservoir combination. Among them, the first two modes together account for 82.5%. This study will enhance unconventional gas utilization and provide a theoretical foundation for understanding the compatibility of superimposed gas-bearing systems in coal measure strata.