Spinning driller and mast amplitude device thereof

The utility model discloses a mast amplitude device, which comprises a mast (1) with a triangular part (2) hinged on the lower part thereof, a mast cylinder (3) with one end hinged with the mast (1) above the hinged point between the triangular part (2) and the mast (1) and the other end hinged with one end of the triangular part (2) away from the mast (1); and when the mast (1) is vertical, the length of a cylinder barrel (31) of the mast cylinder (3) is more than or equal to 70% of the length of the whole mast cylinder (3). The device can efficiently promote the stability of the mast (1) and has simple structure and low manufacturing cost. The utility model also discloses a spinning driller which contains the mast amplitude device.