Abstract: A singularity control strategy for roll-pitch semi-strapdown seeker is investigated and proposed. According to the foundation of target tracking, the model of the roll-pitch seeker stabilized platform was detailed. Singularity characteristics of roll-pitch seeker were analyzed, and the relationship between the parameter varieties and seeker performance was examined. The singularity control strategy for roll-pitch seeker could be worked out by dividing operating zone into three parts and formulating the corresponding control strategies. Simulation results show that the proposed control strategy can effectively restrain the disadvantage of singularity of roll-pitch seeker on seeker performance.