Nowadays, Unmanned Aerial Vehicles (UAV) is increasingly being used in groups, and the number of UAV in cluster is increasing, yet the endurance of UAVs has been the reason that limits its application. In this paper, a cluster strategy of simultaneous charging for laser-powered UAV cluster is proposed to solve the problems of short endurance and low charging efficiency of UAV cluster. The initial position of the cluster charging UAVs are derived through the formula of circle flocking, then optimized by using the Improved Artificial Potential Field (IAPF) combining with the Particle Swarm Optimization (PSO) algorithm and finally the results are verified by MATLAB simulation at last. The results show that in the case of laser beams of 1 and 7 beams, the highest efficiency of clustering is 92.6% and 91.9%, with an average increase of 12.64% and 10.41% in efficiency over the pre-optimization period, and a decrease of 7.06% and 6.27% in spot OD, which gives a better effect of clustering. The cluster charging strategy can address the scheduling problem of the traditional charging method when there are many numbers of UAV swarms, which can be used in the field of UAVs laser charging.