Tool and method for determining circle center of pipe orifice

The invention relates to the technical field of ship construction, in particular to a tool and method for determining the circle center of a pipe opening. The tool for determining the circle center of the pipe opening comprises a disc body, a first identification part and a second identification part are arranged on the disc body, an identification point of the first identification part is located at the circle center of the disc body, the second identification part comprises a through groove and scale marks which are adjacently arranged, and the through groove extends in the radial direction of the disc body. The scale marks are arranged at intervals in the radial direction of the disc body, and the second identification parts are arranged at intervals with the circle center of the disc body as the circle center. The disc body can be fixed to the pipe opening of the pipeline, when the scale marks with the same numerical value in all the second identification parts are aligned with the outer surface of the pi