Disclosed are a method and a device for processing an image by using image division capable of simultaneously minimizing deterioration of an image quality due to an error in a transmission line and further improving compression efficiency in performing compression and restoration of an image signal by using multiple processors. The method of processing an image by using image division according to an exemplary embodiment of the present disclosure includes dividing an image frame into multiple subblocks having a predetermined pixel size; constituting multiple macroblocks by sampling respective pixels positioned at an identical position within a predetermined number of subblocks; and constituting multiple slices by dividing the multiple macroblocks based on the positions of the sampled pixels within the subblock.