Abstract: With the mining method optimization of Zhengjiapo Iron Mine as engineering background, the diamond room sublevel stripping with backfilling is put forward through analyzing the geological features of the gently inclined medium-thick ore-body, such as unstable roof, easily flooding, big water yield, loose deposit, much blocks and broken ore-body.The mining method is suitable for the parts of ore-body with thickness of 6～15 m at dip angle of about 10°, which belongs to the gently inclined medium-thick ore-body.Some stones are removed in the mining process, and loss and dilution tends to be medium balance.This mining method is of great significance to increase the output of the mine and safety production.

Key words: Roof breakage, Refractory ore-body, Mining method, Diamond room sublevel stripping with backfilling