A method for on-line calibration and zoning linear distortion adjustment of image measurement system is proposed.A work with round hole is used as the target

and the central point of work is regarded as characteristic point.During the calibration CCD camera is driven along the track of system to obtain several groups of calibrated points.The calibration parameter of measurement system is calculated according to the calibrated points in the center part.The distortion of each point in the image can be calculated and corrected.