Abstract: Based on the principle of range-Dopple(R-D) algorithm, for low-orbit satellite targets and given azimuth resolution, the accumulation time is analyzed. The result is verified using actual radar and target parameters. According to the algorithm and system parameters, the demanded computation and memory for real-time imaging processing is derived and a multi-channel real-time ISAR imaging system is designed and implemented. The actual experiment has obtained good multi-channel imaging result and indicated that the design is effective.