According to the principle of push-broom imaging of a linear array Time Delay Integration(TDI) CCD, the image motion in dynamic imaging of a agile satellite is analyzed in three-axis attitude maneuvering. As the changed continuously attitude points to the earth can change the spatial orientation and result in a changed image motion velocity, the image quality and image resolution will be deteriorated. To decrease the influence of attitude change on image quality, this article uses the coordinate transformation to acquire the mathematical expression of the image motion velocity in dynamic imaging, and obtains the variety of the image motion velocity in simulation analysis to quantify the magnitude of the integration time. Numerical simulation shows that the current level of space camera can achieve the max angular velocity limit dynamic push-broom imaging of 0.5(°)/s on an orbit height of 700 km. When the attitude maneuvering angular velocity is greater than 0.5(°)/s ,it needs to design a high level camera because the exposure time is shorter and shorter. Based on the above conclusion, it suggests that the magnitude of integration time for TDI CCD TDI) should be quantified for dynamic imaging at different angle speeds, and only in this way can the push-broom dynamic imaging be implemented in three-axis attitude maneuvering.