The invention discloses a composite cutting part for a boom-type roadheader. The composite cutting part comprises a cutting head, a cutting speed reducer, a spindle connected with the cutting head andthe cutting speed reducer, a cutting part power device connected with the cutting speed reducer, a disc milling cutter, a milling cutter frame, a sliding sleeve, a pushing arm connected with the sliding sleeve, a pushing oil cylinder and a cutting arm rack. When coal rock with small hardness is cut, the power of the cutting part power device drives the cutting head to rotationally cut the coal rock through the cutting speed reducer and the spindle; when rock with large hardness is cut, the pushing oil cylinder pushes the milling cutter frame to move forwards, and the power of the cutting partpower device drives the milling cutter frame and the disc milling cutter to rotationally cut the coal rock through cutting speed reducer and the spindle. The roadheader provided with the cutting partcan adapt to rock with different hardness, and the application range of the boom-type roadheader is expanded; and the consumption of cutting teeth is reduced, the time and the labor intensity of replacing the cutting teeth by workers are reduced, the use cost is reduced, and the cutting efficiency is improved.