To address the issue of cooperative route planning for multiple Unmanned Aerial Vehicles (UAVs) to avoid collision, an improved Artificial Potential Field (APF) method combined with Bezier curve is proposed to increase the self-repulsion field of UAVs.Firstly, the general artificial APF that has virtual impact on the UAV is given.In order to prevent inter-UAV collision, the repulsive potential field generated by the UAV itself is defined.The repulsion function produced by the repulsion field is sectionallycontinuous, and thus the occurrence of frequent large angle flight and sharp turning can be effectively avoided while preventing inter-UAV collision.Secondly, to address the problem of APF local optimum, a method based on virtual obstacle is designed to avoid local optimum.Finally, a sectional Bezier curve smoothing algorithm is proposed to smooth and optimize the UAV flight path online in real time.The smoothness of the curve is guaranteed at the joint of the two sectional Bezier curves, and the path oscillation in the route planning is eliminated.The simulation results have proved the effectiveness of the proposed method.