Aiming at the process of executing combat mission, the collision may occur between the UAVs (unmanned aerial vehicles), or between the UAV and the enemy plane. A collision avoidance control algorithm and a control strategy based on the artificial potential field were simultaneously applied for a Multi-UAV collision avoidance control. The three UAVs constituted the triangular formation as the control object, the leader flight path as the expected path, the followers tracked the leader to maintain the triangle formation flight. From the UAV formation encountering the obstacle to the UAV formation system accomplishing the avoidance, the UVA formation experienced three stages, including the merging formation, the splitting formation and the closing rank to the triangle formation, which is the convergence to the steady flight state. The simulation results show that the proposed collision control avoidance strategy can converge to the desired formation and the stability-flight state.