The invention relates to a scrap iron separation device for a coal pulverizing system. The scrap iron separation device comprises a control cabinet, a separation device barrel, a lower connecting pipe, a scrap iron collector, an upper connecting pipe and an electromagnet, wherein the electromagnet is arranged at the periphery of the inner wall of the separation device barrel, the upper connecting pipe is arranged on the top of the separation device barrel, and the scrap iron collector is arranged at the bottom of the separation device barrel; the scrap iron collector is an inclined conical barrel, and the upper end of the scrap iron collector is fixedly connected with the bottom edge of the separation device barrel; the lower connecting pipe penetrates through the scrap iron collector, stretches into the separation device barrel and vertically corresponds to the upper connecting pipe; the electromagnet is connected with the control cabinet. Most of scrap iron in pulverized coal can be separated, the wear of a primary air duct can be greatly reduced, the coking risk of the water-cooled wall of a boiler also can be reduced, a large amount of scrap iron can be recovered, and about 140-ton scrap iron can be recovered each year in a middle storage type coal pulverizing system with a 300000 unit.