Image motion of aerial camera during exposure time leads to the degradation of image quality, so image motion compensation system is essential for aerial camera. Subjective criterion, namely image motion is distinguished by human eyes, is always used to evaluate whether the performance of the image motion compensation system meets the design requirements. Subjective criterion is usually influenced by people, and only provides qualitative evaluation. In order to establish the direct relationship between image quality of aerial camera and other index of image motion compensation system, modulation transfer function (MTF) measurement of image motion based on slanted-edge method is presented. Then experiment is designed to verify this method. Image motion caused by scanning of aerial camera is simulated by the rotation of turntable, and the MTF of image motion is obtained by two ways. One is measured by slanted-edge method, and the other one is calculated by theoretical model. Experimental results show that when spatial frequency is 0.10 cycle/pixel and the turntable rotates at 3, 5, 8°/s, the difference between the MTF obtained by the two methods is 0.77%, 1.15%, and 4.91%, thus the effectiveness of this method is demonstrated.