The invention discloses a liftable petroleum machinery equipment nut mounting and dismounting machine. The machine comprises a first piston cylinder and a mounting and dismounting machine body, wherein a first multi-stage rotating wheel and a second multi-stage rotating wheel are mounted inside the mounting and dismounting machine body; a dismounting gripper is mounted below a second piston cylinder; a second motor is mounted on the right side of the second multi-stage rotating wheel; a driving wheel is mounted on the lower right side of the mounting and dismounting machine body; and a driven wheel is mounted on the left side of the driving wheel by the aid of a conveying belt. According to the machine, a mounting gripper and the dismounting gripper are driven by two motors in opposite rotating directions and cooperate with the piston cylinders for working, so that automatic mounting and dismounting are realized; a force sensing device is mounted above the mounting gripper of the mounting and dismounting machine, after a nut is mounted and fastened, the motor is powered off automatically when the force sensing device senses that the torque is increased suddenly, thus fastening and mounting of the nut can be guaranteed, and the mounting and dismounting machine and the nut can be protected against forced damage.