Special knife for manufacturing stair handrail

The utility model relates to the technical field of stair handrail processing, and discloses a special knife for manufacturing a stair handrail, which comprises a supporting leg, a working box is fixedly connected to the top of the supporting leg, a motor box is fixedly connected to the middle of the right side of the working box, a working cavity is formed in the working box, and an adjusting mechanism is arranged in the working cavity. The cutting mechanism is arranged at the top of the working box, the adjusting mechanism comprises a first motor, a bidirectional threaded rod, a ball nut pair, a connecting rod, a movable plate and a fixed semi-ring, the first motor is fixedly connected to the inner bottom of the motor box, the first motor is provided with an output shaft, and the bidirectional threaded rod is fixedly connected to the output shaft of the first motor. According to the special cutter for manufacturing the stair handrail, when a pipeline needs to be clamped, the pipeline is placed in a fixing s