Aiming at the problems of coal under buildings, railways and water bodies as well as gangue discharge in coal mines, a study was conducted on lane-by-lane gangue backfill mining technology based on the middle strip working face in the southern district of Xinyuan Company. Through material tests, a composite backfill material was determined with 0~20 mm gangue mixed with 15% cement. Based on FLAC3D numerical simulation, the rational parameters were optimized and obtained as a roadway width of 5.6 m and a coal pillar width of 8 m, which effectively controlled surrounding rock deformation and plastic zone development. A lane-by-lane backfill process with synchronous mining and backfilling was designed. Field measurements showed that the maximum surface subsidence was only 33 mm, and the building damage level was Grade I, which verified the feasibility and effectiveness of the technical system in controlling surface subsidence and realizing the resource utilization of gangue.