The circular cutter is placed on the steel plate to be cut through the three support points on its base. The motor drives the radius rod with adjustable length through the gearbox, and then drives the cutting torch to rotate for cutting. It can also cut when the steel plate is placed vertically and at an angle, and can cut concentric circles for gas cutting. The utility model can improve the work efficiency, ensure the quality, and reduce the labor intensity of workers. 1. Silicon controlled speed regulation, mechanical two pole speed change, stable running speed; 2. The bottom of the machine body is equipped with rollers, which is easy to move; 3. The rotary gas distributor is adopted, and the rubber hose is not twisted during operation; 4. Specialized in cutting round parts, round holes, flanges, etc; 5. The machine is made of high-strength aluminum alloy die-casting, light and portable. It is widely used in petroleum, chemical industry, shipbuilding, machinery manufacturing and other fields to cut pipes. 6. Roundness deviation is less than 1mm.