A method for calibrating a laser measuring apparatus having a laser illumination unit and an image capturing unit includes the following steps. A calibration board having at least one slit gap and a plurality of markers is provided. The relative position between the calibration board and the laser illumination unit is adjusted to allow a slit laser beam emitted by the laser illumination unit to pass through the at least one slit. The calibration board is captured by the image capturing unit to generate a calibration board image. The calibration board image is processed so as to obtain a camera coordinate of each of the markers. A plurality of calibration parameters are calculated according to the camera coordinate and an actual coordinate of each of the markers so as to obtain actual coordinates of an object captured in an object image generated by the laser measuring apparatus.