Abstract: Purifying the fine coal from magnetite powder by dry magnetic separation has an important influence on the density stability and magnetite powder loss in continuous fluidization separation.However，feed characteristics has a direct effect on dry magnetic separation.Therefore，the influence laws of coal particle size，fine coal content，magnetite powder water content and magnetite powder particle size in dry magnetic separation were examined in the laboratory.The results show that：①the recovery yield of magnetite powder，fine coal purifying efficiency and magnetic separation efficiency gradually decrease with the content of fine coal increasing from 4% to 20%；②with the increase of magnetite powder moisture，the recovery yield of magnetite powder gradually decreases；③the purifying efficiency of fine coal，magnetic separation efficiency firstly increase and then decrease with the increment of magnetite powder moisture.The recovery yield of magnetite powder，the purifying efficiency of fine coal，magnetic separation efficiency rapidly increase and basically stabilize with the increasing size fraction of particle size of fine coal or magnetite powder.