Abstract: To safely recover the coal resources trapped under the protective coal pillar of the auxiliary inclined shaft, the deformation and stress response patterns of the shaft during unitized dense backfill mining are investigated. Taking the 1305 working face of a mine in the Yushenfu area as the engineering background, a three-dimensional model was established using FLAC^3D to simulate the full four-stage mining and backfilling process with a “mining 8 m and leaving a 24 m pillar” layout. The evolution of the displacement and stress fields of the auxiliary inclined shaft was analyzed, and on-site monitoring covering the entire mining period was conducted for verification. After the completion of mining and backfilling, the maximum vertical settlement of the shaft was 11.1 mm, the horizontal deformations in both the X and Y directions were less than 2 mm, and the stress fluctuated only slightly without obvious stress concentration. The measured maximum cumulative settlement was 9.446 mm, the inclination deformation was generally lower than 3 mm/m, and the maximum curvature was less than 0.3 mm/m². All indicators satisfy the Grade I protection standard for buildings (structures), and the measured results are generally consistent with the simulated ones. Through the synergistic bearing of the reserved coal pillar and the consolidated backfill, the overlying strata movement and mining-induced disturbance can be effectively suppressed, thereby achieving the safe recovery of the trapped coal resources while ensuring the stability of the auxiliary inclined shaft.