In the air defense warfare under information-based condition, establishing detect & surveillance network is the technical guarantee of capturing informational preponderance.Meanwhile,realizing scientific and reasonable allocation of sensors resource is the important method of promoting the efficiency in gaining the air defense detect & surveillance network information. In order to make full use of the function and the performance of air defense detect & surveillance network, we have to allocate the limited sensors resource scientifically and reasonably in the phased-array radar network so as to improve the whole effectiveness of detect & surveillance network and furthermore to improve air defense warfare effectiveness. In view of the phased-array radar network multi-sensors resource management optimization problem, the phased-array radar characteristic and the network significance are introduced, and a relative entropy multi-sensors management algorithm based on phased-array radar network is proposed. By using this algorithm, each sensor to each goal greatest information content is obtained by calculating the sensor-to-goal indetermination of relative entropy, then taking this as the price function, the multi-sensors to the multi-goals optimized assignment is performed, and the simulation result indicates that this algorithm is valid and effective.