In recent years, significant breakthroughs have been made in shale gas exploration within the Upper Permian Dalong Formation of western Hubei Province. To comprehensively investigate the multi-component gas adsorption characteristics, genetic mechanisms of shale gas, and hydrocarbon potential of the Dalong Formation in the western Hubei region, we conducted on-site gas desorption experiments using the water displacement method at shale gas well locations, and performed detailed compositional and stable isotopic analyses of the collected desorbed gases. The results indicate that during the desorption process, the proportion of CH? initially decreased with prolonged desorption time but exhibited a distinct upward trend once the desorption temperature reached 85°C. In contrast, C?H?, C?H? and CO? displayed variation patterns opposite to methane. Both methane and ethane show significant carbon isotopic enrichment: methane δ13C values increased from -38.64‰ to -30.94‰ to -22.46‰ to -4.56‰, representing an enrichment of 13.70‰ to 26.38‰, while ethane δ13C values rose moderately from -46.39‰ to -36.83‰ to -36.94‰ to -28.24‰, accompanied by a carbon isotope reversal phenomenon. In contrast, methane hydrogen isotopes shifted from -151.11‰~-144.81‰ to -138.82‰~-126.70‰. Further analysis of the experimental data reveals that the adsorption capacity of the shale follows the order: H? > CO? > C?H? > C?H? > CH? > He. The research indicates that the shale gas is highly mature, formed by a mixture of primary kerogen cracking gas and secondary oil cracking gas, with kerogen cracking gas being the dominant component. Additionally, during the desorption process, the hydrogen isotope of methane showed a strong positive correlation with shale gas, making it a key indicator for identifying "sweet spots".