Abstract: In this paper, an approach is presented to calibrate the distortion of CCD array digital cameras. Firstly, we use standard 3D calibration objects to determine the internal geometric and optical camera’s characteristics. Secondly, according to the principle that the projection of every line in space onto the camera is still a line if a camera follows the pinhole model, we propose a new method for calibrating the random distortion with good precision. Finally,we apply the approach to the calibrating process of the digital camera of UAVRS-Ⅱ system. Experiment results indicate that this kind of calibration method have reached successful test effect.