The composite vertical take-off and landing fixed-wing UAV is a compound UAV with the performance of multi-rotor UAV and fixed-wing UAV. Its innovation lies in clarifying the influence of rotor installation location on the overall performance of UAV.Aiming at the complex aerodynamic interaction between rotor and wing of this kind of UAV.In this paper,the aerodynamic characteristics were analyzed by experiments and Computational Fluid Dynamics(CFD). The installation method of the rotor was determined, and the installation distance of the rotor was further determined based on the level flight status of the UAV. Experiment and numerical simulation results show that the rotor mounted under the wing is more efficient than the rotor mounted above the wing, and the installation distance between the rotor and the wing have a certain influence on the lift of the rotor and the flight performance of the UAV.