In order to provide a method for accurately correcting surface shape data of an annular rotating body, in correcting three-dimensional shape data on a surface of the annular rotating body, a reference line is set along the surface to be detected of the annular rotating body, and then reference equiangular division points, which divide the reference line by equal angles, are set. Next the circumferential length of the reference line is calculated from the distance between adjacent reference equiangular division points, and a plurality of reference equidistant division points, which divide the reference line into equal lengths, are set on the reference line, using the circumferential length. Then interpolation points for correction of the data on the surface to be detected of the annular rotating body are set at positions a preset distance apart in the radial direction of the rotating body from the reference equidistant division points. Then three-dimensional shape data at the interpolation points are calculate
