The utility model discloses a cutting disc of a cutting machine. The cutting disc of the cutting machine includes a sawing disc (1), an inertia disc (2), a connecting bolt (3), an engine base (4), an engine base bearing (5), sawing teeth (10), a rotating shaft (11), an upper positioning gland (12), a lower positioning gland, a stop and locking nut, a rotating shaft end screw, an upper positioning gland inner hole (20), an upper positioning gland hexagonal hole (21), and an upper positioning gland inner ring (22). The cutting disc of the cutting machine is characterized in that a moving cutter blade (6) and a moving cutter holder (7) are fixed on the rotating shaft (11) through a moving cutter fastening bolt (9), a fixed cutter blade (8) is fixed on the engine base (4) through welding, a notch (23) is formed in the upper positioning gland inner hole (20), a notch is also formed in the lower positioning gland inner hole, a fastening pressing piece inner tongue (16) on a fastening pressing piece (14) extends into the notches (23) in the upper gland inner hole and the lower gland inner hole, and fastening pressing piece outer stop and locking pieces (15) on the fastening pressing piece (14) are bent to press the stop and locking nut.