Abstract: A cooperative multi-task assignment problem (CMPAT) model is designed for battlefield environment of multi-objective, multi-task and limited capacity of unmanned aerial vehicle (UAV). According to the task sequence constraint, the cooperative task constraint, and the UAV capacity constraint in the CMPAT model, the chromosome coding method based on task sequence and the cross and disturbance operators based on same category tasks changing are proposed. With the feature of global searching optimal solution of genetic algorithms, this algorithm can optimize the cooperative multi-task assignment of UAVs cluster. Simulation shows that the proposed algorithm can achieve more optimized solution of cooperative multi-task assignment.