A slitting mill is composed of a machine seat (1), a gear box (2), slitting cutters (3), abutting plate wheels (4), a driven shaft (5), a driving shaft (6), a cone pulley (7), a belt (8), a motor (9) and a transmission gear (10). According to the slitting mill, the abutting plate wheels (4) are respectively arranged on the one sides of the two slitting cutter (3) arranged vertically facing to each other. According to the structure, due to the fact that the abutting plate wheels (4) arranged on the one sides of the upper slitting cutter (3) and the lower slitting cutter (3) abut against a steel plate arranged on cutter point portions of the slitting cutters to prevent the steel plate from up warping and deforming, the problem of tearing the steel plate is solved when the slitting cutters (3) cut the steel plate. The slitting mill is simple in structure and good in using effect.