Method for measuring keyway symmetry degree of shaft part

The invention belongs to the technical field of measurement of the keyway symmetry degree, and particularly relates to a method for measuring the keyway symmetry degree of a shaft part. The method comprises the steps that (1) the height H of a central line of the shaft part is measured, (2) the height h of the central line of a measurement block is measured, (3) the distance X between the central line of the shaft part and the central line of the measurement block is calculated, and the distance X is compared with the distance X' between the central line of an axial part and a measurement block on a design drawing, so that the deviation of the keyway symmetry degree is determined. The keyway symmetry degree is measured by utilizing keyways and the measurement block, the keyway symmetry degree of the axial part can be accurately measured without professional measurement devices and gauges, workpiece parameters can be quickly and accurately measured in a simple method, and the method solves the problems that when a three coordinate measuring system is used for measuring the keyway symmetry degree of the axial part multiple times, the measurement results are poor in uniformity and the small-keyway symmetry degree can not be measured.