Gangue and fly ash combined mining technology is the direct filling of the gangue and fly ash to the surface by the feed delivered to the face well, and then filling is in gob areas, while ensuring under the premise of the safe use of surface buildings subjects to the normal maximum level for achieving Coal Mining under the buildings. In the paper, gangue and fly ash on the exploitation of the feed system were designed for filling and compaction equipment, the hydraulic mining was developed on the backfill mining, the conveyor was modified, and the gangue and fly ash mining technology were designed. As the result, the filling rate and surface subsidence was controlled effectively, the service life of the mine was extended, and the good economic and social benefits were achieved.
