Abstract: In multi-radar collaborative detection scenario, multi-task optimal assignment becomes complexity due to the coexisting of multiple cooperative modes. To solve this problem, a multi-radar collaborative task assignment algorithm is proposed in this paper, and a gain function of collaborative strategy is constructed based on detection efficiency, usable collaborative modes and the numbers of participant nodes. Then the multi-task assignment problem is converted to a combinational optimization problem, and a swarm intelligence optimization algorithm is used to solve this problem efficiently. Simulation experiments demonstrate that the proposed algorithm can schedule multi-radar collaborative tasks effectively, and satisfied the requirement of online real-time task scheduling.