Passive sensor cueing of Active Electronically Scanned Array (AESA) radar searching on specified regions is an important application form of airborne multi-sensor cooperating. In comprehensive consideration of the cueing sensor observation error and target's velocity error, a successful cueing probability density model is established. An optimized target searching strategy satisfied the requirement of timeliness, successful cueing probability and false cueing probability is presented. The searching strategy and performance index are calculated under multi-scenario by using the stepwise optimization method. The simulation result shows that in comparison with the traditional method the proposed method can meet the requirements of successful cueing probability, through increase little beam positions and simultaneously can decrease the false hand-off probability obviously.