Abstract: In view of the actual condition of water-rich thick complex ore-body developed in cavity region in Banmiaozi gold ore，and with the aid of advanced large trackless mechanized equipment including deep hole drill rig，charging trolley，remote scrapers，wet spray trolley and others，the mining method of large diameter long hole drilling with subsequent backfill was successfully carried out.The flat floor structure proposed is simple in construction with less mining and stoping engineering quantities.Mechanized charging up with bulk Anfo by charging trolley and millisecond blasting with high-precision digital detonators make the maximum explosive payload reach 10 t at single blasting and blasting amplitude within 0.3 cm/s.A well can be formed at a time by small section of cutting at 4㎡ and 30 m in height.According to different locations and volumes of cavities，the production capacity of per stope reaches 2 000 t/d through stoping sequence optimization，holes reparation，and holes stripping and drilling from adjacent stopes for blasting，and achieves the mining recovery rate of 94% and the dilution rate less than 7%.

Key words: Gold mine, Mining method, Large diameter long-hole open stoping, Subsequent backfill