Abstract: Mining inclined medium−thick fractured ore bodies presents challenges, including poor rock stability, geotechnical hazards in stopes, and low resource recovery rates. This study integrates engineering geological surveys, rock mechanics testing, Mathews stability graph method, Q−system, RMR classification, and numerical modeling to investigate the mechanical properties, stope stability, and backfill strength requirements using a tungsten mine in Hunan as a case study. Key findings reveal: (1)Vertical heterogeneity in rock mass quality−basal granite exhibits optimal stability (UCS =108.62 MPa), while mineralized slate is the weakest (3.67 MPa), with a self−supporting time limited to 37 days; (2) the allowable exposed area of a stope is positively correlated with the rock mass quality. For granite stopes, the span can reach 18 m and the height 40 m, whereas for fractured ore bodies, the span must be controlled within 13−14 m, combined with short−cycle backfilling (≤30 d) and joint shotcrete−bolt−mesh support; (3) identification of 18m as critical span threshold, beyond which the plastic zone expands >50%, and 40 m−high stopes show a 40% increase in stress concentration compared to 20 m scenarios. The study proposes a “differentiated backfill strength design”: 2.5 MPa for primary stoping, 0.5 MPa for secondary stages, and 1.38 MPa for layered backfill, coupled with an innovative graded binder−tailings ratio control system. These measures increased ore recovery from 40% to 88% while reducing dilution from 15% to 6%. A zoned backfill technology framework was developed based on mining phases and spatial positions, developing an “optimized delayed backfill method” with stoping−backfill synergy. The results provide theoretical and practical guidance for the safe and efficient mining of similar complex deposits.