In the way of pursing large width and high resolution imaging, ground imaging distortion is an important factor that needs to be eliminated, therefore, a zoom scanning combine with adjustable slit diaphragm imaging method was proposed in this paper. The corresponding control formula of zoom scanning and slit were deduced. Results show that, under appropriate controlling, this method could effectively reduce the ground distortion brought by the increase of the scanning angle and can maintain the ground resolution to be unchanged (same as the resolution under sub-satellite point) during a wide scan imaging process. Besides, a zoom swing scanning imaging system was designed to verify the feasibility of our method in large width and high resolution imaging applications. This is of great significance for the development of large width and high resolution imaging observation.