Abstract: Coal mining has led to severe issues of surface subsidence and coal gangue accumulation. This paper explores the theoretical framework and technical system for gangue backfilling and reclamation in subsidence areas, including analyses of gangue characteristics, subsidence hazards, fundamental concepts of land reclamation, relevant theoretical foundations, gangue classification and pretreatment techniques, site selection and preparation for backfilling, backfilling and reclamation processes, as well as monitoring and evaluation of reclamation quality. Through comparative analysis of engineering case studies, the feasibility and effectiveness of gangue backfilling for subsidence area reclamation are demonstrated. Future efforts should focus on advancing technology development and application, improving the quality of reclaimed land, achieving efficient resource recycling, and promoting sustainable development in mining areas.