To obtain the perfect exposure in a wide illuminance range at a short period, an adjustable exposure system was designed for an area CCD camera in combination of a single curtain type shutter with controlling exposure by CCD gain. The effect factor on aero photographing process was analyzed, and a exposure expression was work out according to exposure principle of the single curtain type shutter. After confirming the optimized exposure amount of a CCD, the relationship among the slip rate, CCD gain and the illuminance of the ground target was established according to the exposure expression. Furthermore, the signal of a ground target illuminance was collected by a photosensitive resistance, then the signals were used to control the slip rate and the CCD gain. Finally, the rate accuracy of shutter roll shaft was tested at the input rates of 6 300, 4 170 and 1 200 r/min, respectively. The result shows that the rate accuracy of shutter is 0.033, and the exposure accuracy is 0.091 according to combination of the computation results and exposure errors. A ground test on photographing was performed in a laboratory, and the results indicate that the exposure amount obtained is 1 833 DN and the exposure accuracy is 0.066. These results demonstrate that the method proposed can allow the CCD to obtain a proper exposure and captured images can meet the demands of CCD cameras.