Abstract The features of the linearly modulated frequency stepped radar signal (LMFS) and imaging based on it are analyzed. A feasible scheme of target motion compensation is proposed by using designation of radar transmitting signal; ISAR image is achieved by two methods of ISAR image combination for LMFS. The effectiveness of the scheme of target motion compensation is shown by the theoretical analysis and processing of the practical data, and the effectiveness of these methods of ISAR image combination are shown by the theoretical analysis and computer simulation.