Abstract: Based on blast furnace slag as the main cementitous material，with fly ash mixed in a definite percentage of iron mine tailings as the aggregate，through the excitation effect of varieties activators，the strength of the filling body in early stage can be made.Standard curing in 4 hour，the strength can achieve more than 0.3MPa，which can meet the characteristic of high strength in early stage in some mines.Furthermore，the cement used in the backfilling mining process can be substituted by the blast furnace slag as the cementitous material.The industrial waste could be taken full advantage of with the cost of backfilling mining process reducing.

Key words: Blast furnace slag, Fly ash, Cementitous material, Low cost