Abstract: Ludi Iron Mine belongs to the extremely unstable ore-body because of its fractured joints，poor coherence，and crushed rocks.The roof caving and side-fall phenomenon often happen in mining process with low production efficiency.In view of these unfavorable circumstances，the engineering geological conditions and mining technical conditions are investigated in detail through on-site investigation，laboratory tests and numerical simulation.A new proposal of “a half-light blast tunneling controlling the roadway，long advanced bolts actively supporting the roof，fiber reinforced shotcrete supporting the surrounding rocks at route，and the upward drift backfill mining with roof unconnected” is put forward.It has been applied in field test at 2073 and 2074 working faces of 190 m sublevel in Ludi Iron Mine.Roof-contacted filling was dropped from 3 times to 1 in one sublevel vertical height，and 2 times of backfilling was reduced at each stage.It simplifies the construction process and makes the production safer.The new proposal significantly improves the mining efficiency by 50% with good technical and economic benefits achieved.

Key words: Unstable ore-body, Upward drift, Backfill with roof unconnected, Fiber concrete support