Round tube line drawing tool

The utility model relates to the technical field of boiler equipment, and provides a round tube line drawing tool which comprises a center rod. The positioning piece is arranged at one end of the center rod and is suitable for fixing the center rod on the pipe wall of the circular pipe; one end of the cantilever rod is connected with the center rod, and the cantilever rod is perpendicular to the center rod; the connecting part of the line drawing rod is connected with the cantilever rod, the line drawing rod can slide in the extending direction of the cantilever rod, the line drawing rod and the center rod are arranged in parallel, and the action part of the line drawing rod is suitable for drawing lines on the pipe wall of the circular pipe. When the circular tube line drawing tool is used for drawing lines, after the position of a center line of a hole is determined on a circular tube, the center rod is fixed on the circular tube through the positioning piece, so that the distance between the center rod and