The invention discloses a cutting machine for cutting a structural wall pipe. The cutting machine comprises a mounting frame, wherein two supporting cross rods are fixed on the mounting frame, two belt conveying assemblies are arranged on the supporting cross rod, the belt conveying assemblies are in threaded connection with threaded rods through connecting longitudinal rods, a top supporting plate is fixed to the top of the mounting frame, a lifting air cylinder is fixed to the top supporting plate, a first motor mounting plate is fixed to an end of an output rod of the lifting air cylinder,a cutting motor is fixed to the first motor mounting plate, and a cutting blade is fixed to an output shaft end of the cutting motor. The cutting machine is convenient to adjust, structural wall pipescan be conveniently cut and fixed, and thereby the structural wall pipes are prevented from moving in the cutting process, the cutting effect is guaranteed, resistance of the structural wall pipe during moving is minimized, the service life of the cutting machine is guaranteed, the structural wall pipe can be automatically conveyed and collected, labor intensity is reduced, and production efficiency is improved.