In order to adapt the optic intensity variation of the environment and to obtain stable and high quality image features, an automatic control algorithm on CCD camera electric shutter is proposed. This algorithm mainly consists of two parts: auto shutter control (ASC) based on cubic interpolating polynomial of common logarithm of the image average gray and image grey stretch technique based on experiment data analysis. The experimental result shows that the proposed algorithm has fast and stable convergences, and those captured images by using this technique have good quality and adaptability at different environment illumination.