As the research carrier of model flight test, it is very important to study the flow field and aerodynamic characteristics of typical unmanned aerial vehicle (UAV). The purpose of this paper is to deeply analyze the aerodynamic characteristics of typical layout UAV under the flow conditions of Mach number Ma = 0.2 and Reynolds number Re = 4.3 × 106 , focusing on the influence of angle of attack (AoA) on the lift-to-drag ratio, surface pressure distribution and flow field structure of UAV. The high-precision numerical simulation method is used to systematically evaluate the flight performance at different angles of attack. The results show that when the angle of attack is about 3◦ , the UAV can achieve the optimal lift-drag characteristics, and with the increase of the angle of attack, there will be a λ-type streamline distribution on the wing surface. In addition, the evolution of the vortex structure of the UAV under unsteady high angle of attack conditions is discussed in depth, and the relationship between the vortex structure and the aerodynamic characteristics of the UAV is revealed.