Abstract: Because covariance control strategy cannot meet the real-time requirements of tracking target for phased array radars, this paper uses the methods of combining covariance and target threat degree to study the issue of beam steering. An optimal model of beam scheduling is established. The model utilizes the information of target motion state, including the distance of target, the target radial velocity, acceleration and direction, to determine the target threat degree by analytic hierarchy process, and then combines with target tracking covariance, further determines the priority of targets, to achieve the adaptive beam scheduling in the dynamic search and track mode (TAS). Comparing the proposed algorithm with the traditional beam scheduling method , the simulation results show that this algorithm can not only have higher time efficiency, but also have a good tracking performance.