Abstract: Space-based early warning radar uses satellites as the carrier, which can break through the territorial restrictions and achieve surveillance of moving targets regardless of the time and weather. This paper takes the aerial moving target indication as the application scenario, and proposes a sector division and beam position arrangement method, which can compensate the beam footprint movement caused by high-speed motion of satellite. As a result, this method can ensure the full coverage of search area with beam positions as least as possible, and meets the practical engineering needs of on-board real-time processing.