Digital microthruster arrays can be used to propel micro/nanosatellites on missions requiring high precision and low impulse. This paper presents a novel control allocation strategy for digital microthruster arrays, called segment distribution and stratification addressing (SD-SA) algorithm, which aims to find the optimal combination of microthrusters to successfully achieve a given thrusting maneuver. The SD algorithm separates a thruster array into disjoint segments, and then the SA algorithm combines these segments to provide required impulses in a control task. Compared with traditional algorithms, the SD-SA algorithm costs less time and computational storage space. It is demonstrated through simulation that the SD-SA algorithm is effective for the real-time orbit control of micro/nanosatellites.