A method of correcting a change of position of a machine tool having at least two control axes avoids abrupt machining errors. A position correction means (12) outputs correction pulses (Xcp, Ycp) so that the ratio of actual amounts of movement of the respective axes, obtained from the output values of position detectors (8X, 8Y) detecting a position of the machine tool, becomes equal to the ratio (R1) of distribution pulses (Xp1, Yp1) for the respective axes. The correction pulses (Xcp, Ycp) are added to the distribution pulses (Xp1, Yp1). Accordingly, an abrupt machining error caused at the beginning or just before the end of machining, or when machining a corner of a workpiece, is alleviated.