Abstract: To delve into the impact of roof structural plane inclination angles on the mechanical properties of coal and rock during coal extraction, this study employed a bespoke acoustic process simulation testing system for conducting true triaxial loading and unloading tests on combined coal and rock specimens under varying structural plane inclination angles, with an acoustic emission detection system for monitoring. Findings indicate that with increasing inclination angles, the specimens' failure strength diminishes and crack development weakens. The failure mode shifts from tensile shear to shear failure, culminating in sliding failure at an inclination angle of 40°.Specimens with an inclination angle under 30° experienced ample plastic deformation, optimizing their loadbearing capacity, whereas those with inclination angles of 30° or more encountered rapid failure upon reaching critical failure thresholds, leading to partial or complete sliding failure. Acoustic emission signals were predominantly observed during the unloading failure phase, with fewer cumulative counts recorded for specimens at higher inclination angles. At a 40° inclination, sliding failure significantly reduced the maximum ringing count, marginally affecting the cumulative count. These insights provide valuable perspectives on the unloading failure mechanisms triggered by the inclination angle of the roof structural plane, contributing to the advancement of safe mining practices.