The invention discloses a combined corn milling cutter. The combined corn milling cutter comprises a clamping end and a cutting section, wherein multiple chip removal slots and multiple cutter groups are arranged on the cutting section; each cutter group comprises multiple cutter teeth arranged in the spiral direction of the chip removal slots, the cutter teeth in each cutter group are distributed at intervals, cutter teeth of two adjacent cutter groups are arranged in a staggered manner, and the distance between every two adjacent cutter teeth of the same cutter group is smaller than the length of each cutter tooth; cooling channels and guide holes communicating the cooling channels and the chip removal slots are formed in the cutting section, and a fluid inlet is formed in the clamping end. Torsional force produced on the cutting section is reduced by means of the staggered chip removal slots and cutter teeth, so that the service life of the cutting section is prolonged; the good cooling and lubricating effects are realized by means of the cooling channels and the guide holes; by means of obliquely arranged cutting edges, wear of the cutting teeth can be reduced, and the service life of the cutting teeth is prolonged.