In order to improve the automatic light adjustment for traditional CCD camera system in engineering,a new full-automatic light adjustment method for CCD camera system was presented.In this method,light was adjusted by combining external trigger electronic shutter mainly and iris diaphragm assistantly.For obtaining a moderate image illumination,the electronic shutter time of CCD camera was adjusted by external trigger and the aperture of iris diaphragm was adjusted by motor controlled by single-chip.Feedback control quantity was obtained from the mean level of target region of image,so that the full-automatic light adjustment was implemented.Matlab simulation results show that histogram related to image of new light adjustment system is wide and uniform,and the peak value of its power spectrum is more than 7.5 dB.The image of the new light adjustment system is clean and high-contrast,which shows new system can satisfy requirements of the optimal full-automatic light adjustment for modern CCD camera system.