The basic Differential Evolution (DE) algorithm has the problems of insufficient search accuracy and convergence ahead of timewhich results in unsatisfying effects of 3D path planning.Thereforea modified differential evolution algorithm based on Sine Cosine Algorithm (SCA) is designed.Firstlythe mutation strategy is improved based on the search mechanism of SCA as well as the populations center of gravityand the crossover strategy is improved by integrating the disturbance strategyso as to improve the search ability and convergence performance of the algorithm.Thena new scaling factor is designed based on the Logistic functionso as to resolve the contradiction between global and local search.Through the experiment of function optimizationit is verified that the modified algorithm has good search accuracy and convergence rate.Finallythe modified algorithm is applied to 3D path planning of UAV.Owing to the advantages of the modified algorithm in searchingthe surrounding spatial environment can be better distinguished in each generation of searchso that the path selection is more reasonable.The simulation results show thatcompared with that of the basic differential evolution algorithmthe 3D path of UAV generated by the modified algorithm is shorter.