The study investigates the compressive properties of coal under water-gas coupling conditions using a water-rock-gas coupling test system. The research analyzes the compressive strength and deformation damage characteristics of coal samples, revealing the macro and fine degradation mechanisms under these conditions. The results show that the compressive strength of coal samples decreases compared to dry samples, and the damage mode shifts from tensile damage to mixed shear-tensile damage. Coal samples also transition from brittle to plastic damage, increasing the range of localization zones and misalignment. The deterioration effects in three soaking environments are primarily attributed to the decomposition and precipitation of clay minerals, surface deterioration, and changes in the internal pore structure. These changes reduce the coal samples' ability to store energy before failure. The study highlights the importance of understanding these degradation mechanisms for the stability of coal rocks in gas-rich underground mines.The study investigates the compressive properties of coal under water-gas coupling conditions using a water-rock-gas coupling test system. The research analyzes the compressive strength and deformation damage characteristics of coal samples, revealing the macro and fine degradation mechanisms under these conditions. The results show that the compressive strength of coal samples decreases compared to dry samples, and the damage mode shifts from tensile damage to mixed shear-tensile damage. Coal samples also transition from brittle to plastic damage, increasing the range of localization zones and misalignment. The deterioration effects in three soaking environments are primarily attributed to the decomposition and precipitation of clay minerals, surface deterioration, and changes in the internal pore structure. These changes reduce the coal samples' ability to store energy before failure. The study highlights the importance of understanding these degradation mechanisms for the stability of coal rocks in gas-rich underground mines.