Abstract: The remote sensing imaging process is analyzed. The image degradation model is introduced. On the basis of discussing the cloud transmission function, the method of remote sensing imaging simulation is proposed in the three cases that the clouds are evenly, gradually or locally distributed. The problem lacking reference images is solved during the studies of the cloud removal algorithms for single images. Detailed simulation procedures and implementation methods are presented. Experiments prove that the proposed method has good running efficiency and low cost. It provides large amount of images with various cloud distributions for the test and objective evaluation of cloud processing algorithms for single images, and promotes the studies on the corresponding technologies.