Increment angle instruction of polar coordinate seeker is not appropriate to plan dynamically as seeker itself rolls greatly during tracking process. In the paper, an angle instruction scheme based on full-map plane was first introduced, and then a strategy for target tracking in zenith blind zone was presented. The angle instruction calculation's key point is to optimize instruction by rotating the full-map plane coordinate system. After analysis of target's move patterns, tracking strategy for blind zone was constructed by improving criteria for rotating full-map plane coordinate system during instruction's optimization and by holding roll instruction under specific situation. The simulation by Matlab demonstrates that the strategy can reduce the maximum dislocation angle during target tracking, accordingly can reduce the probability of track loss.