The utility model discloses a cutting machine for a groove of a steel pipe welded specimen. The steel pipe welded specimen with the groove is machined for training electric welding skilled workers, and machining expenses for the welded specimen are lowered. The cutting machine comprises a flame cutting machine and a cutting running trolley, and running wheels are installed at the two ends of a running wheel installation shaft of the cutting running trolley. The cutting machine is further provided with a specimen clamping device, the flame cutting machine is fixed to a tank of the specimen clamping device, one running wheel of the cutting running trolley is connected with a rotary transmission mechanism of the specimen clamping device in a rolling mode, a specimen rotary transmission gear is installed in the middle of the running wheel installation shaft, the specimen rotary transmission gear is meshed with a transmission gear on an output shaft of a gear case of the cutting running trolley, and power is provided for the rotary transmission mechanism. The steel pipe welded specimen is machined through existing electric welding equipment and the specimen clamping device. The operation process and the cutting process are stable, the size precision is high, the specimen can be machined at any time according to actual requirements, and the machining cost is lowered significantly.