Cutting machine special for steel pipes

The invention relates to the field of mechanical equipment, and discloses a cutting machine special for steel pipes, which comprises a portal frame. A steel rail is paved below the portal frame, and is provided with two trolleys; and each trolley is provided with a positioning brake device. The cutting machine is characterized in that: a, each trolley is provided with a pair of riding wheels by a bracket respectively; a catch wheel is arranged at the front end of one trolley; at least one riding wheel of the two pairs of riding wheels is a driving wheel and is provided with a speed reducer and a motor; b, the portal frame is provided with a lifting beam matched with a lifting mechanism; the lifting beam is provided with a horizontal slide bushing matched with a horizontal driving mechanism; and the horizontal slide bushing is fixedly provided with a grinding wheel cutting machine of which grinding wheels are arranged downwards. The cutting machine special for the steel pipes solves the problem that a conventional chain-type universal pipe cutting machine is difficult to adjust a pipe cutting length, cuts the pipe at a low speed and cannot ensure the cutting size accuracy of the pipe, and is mainly used for the length cutting of centrifugal ductile iron pipes.