Great uniformity of exposure is essential to get high quality aerial photograph.A measurement method of effective exposure time on curtain shutter is raised,which is based on analysis and calculation of effective exposure time on aerial camera shutter.Using multiple metering at each position of different aperture,and according to photoelectric method,a fitting curve of aperture and effective exposure time is obtained applying leas-squares techniques,comparing which to theoretical curve,non-uniformity degree of exposure could be judged.Finally,results of testing a curtain shutter is shown that non-uniformity of exposure is 2.8%,which could meet the required precision of 4%.The photogragh we get from aviation experiment can be satisfied for the aim distinguished.