In the combat system of radar,the reasonable scheduling of beam resources has always been a key issue.In this paper,the covariance algorithm and the gray relational algorithm are combined to implement the beam resource allocation of the radar system.It can maximize the utilization of beam resources while satisfying the tracking accuracy of each target.To the multiple targets being tracked,the threat degree of each target is calculated by using gray relational algorithm,and the expected covariance is set according to the target's threat degree.The difference between the expected covariance and the actual covariance is calculated for each target,and all the differences are ranked from large to small.The target with the biggest difference is taken as the object for tracking.If all the targets reach the desired value,the radar will detect new targets.The proposed algorithm can realize the adaptive allocation of the radar system's beam resources.