The invention relates to a method for measuring the shape of a workpiece in a machine tool which is provided with an on-machine measurement device and is controlled by a numerical control device. The method comprises the following steps: determining a reference point for temperature drift correction in advance on the workpiece, moving a probe towards the reference point, resetting a coordinate system of the probe, correcting the temperature drift of the probe, firstly carrying out shape measurement on the workpiece along a first measurement path, then moving the probe to the reference point, resetting the coordinate system of the probe, then correcting the temperature drift of the probe again, carrying out shape measurement on the workpiece along a second measurement path, and then carrying out the same temperature drift correction on each measurement path before carrying out shape measurement on the workpiece along a final measurement path.