For the aerodynamic layout selection of a long-endurance hydrogen energy hybrid unmanned aerial vehicle(UAV), this paper carried out a numerical simulation of aerodynamic characteristics for a certain design plan, in order to provide data support for the aerodynamic layout design evaluation and modification work. In the study, the aerodynamic data at 11 angles of attack (-6°~14°) were analyzed, the results of two turbulence calculation models were compared, and the respective lift-drag characteristic curves were obtained. In addition, the flow details such as velocity field, streamline, pressure cloud graph, and pressure curve distribution, were analyzed in detail. The results show that the UAV has a high aerodynamic performance, the maximum lift-to-drag ratio 14.5 can be obtained under the attack angle of 4°, and the stall angle of attack is 8°. The aerodynamic layout design basically meets the requirements. At the same time, the distribution characteristics of speed, pressure, and flow separation are of great significance for further understanding the aerodynamic performance of the UAV.The assessment results provide a basis for the subsequent improvement of the aerodynamic layout plan.