The invention discloses a continuous pipe cutting machine which comprises a gear box, a servo motor, a power transmission mechanism, crank mechanisms, an annular sliding groove and saw blades. The servo motor is fixed to one end of the top surface of a box cover, a control input gear is arranged on an output shaft of the servo motor, a worm mechanism is arranged on the upper portion inside the gear box, and a guiding gear is arranged at one end of the worm mechanism and meshed with the control input gear. A hollow main shaft is arranged in the center of the box cover, the power transmission mechanism is arranged on the hollow main shaft and meshed with the worm mechanism, and the three crank mechanisms are arranged on the power transmission mechanism. Each crank mechanism is provided with the saw blades and a small crank shaft, the annular sliding groove is formed in the side face of the gear box, and the end of each small crank shaft is connected with the annular sliding groove in a sliding mode. The hollow main shaft not only can have the effects of a shaft, but also is a feeding port. Pipe cutting work can be rapidly finished, automatic tool advance and tool retracting are achieved, and the continuous pipe cutting machine has the advantages of being simple in structure and low in manufacturing cost and is suitable for being used for various scales of factories.