Tilt rotor unmanned aerial vehicles combine the advantages of helicopters and fixed wing aircraft, solving the problems of low flight speed and harsh takeoff conditions of conventional helicopters. Compared with traditional configuration tilt rotor aircraft, they can significantly improve the aerodynamic interference of rotor downwash airflow on the wings in hovering state, improve flight efficiency, and have broad development prospects in military and civil aviation fields. In response to the problem of the continuous tilting transition process of this configuration of unmanned aerial vehicle with complex and unsteady aerodynamic characteristics, this paper replaces the real blade with a virtual propeller disk model, calculates the rotor flow field by adding momentum source terms, and combines dynamic grid technology to perform unsteady aerodynamic simulation of the flow field. The aerodynamic interference and lift resistance characteristics of the flow field near the rotor/fixed wing are calculated and analyzed, and the model is established and the forward flight speed tilt angle motion equation is iteratively fitted for the transition section motion state. The simulation calculation results show that the initial tilting state of the unmanned aerial vehicle is less affected by the downwash flow of the rotor, and the main lift is provided by the fixed wing. During the tilting process at a tilt angle of 30 ° -50 °, the resistance of the tilting rotor wing section increases, and the required pulling force of the rotor increases. The lift of the outer section of the tilting wing decreases due to the interference of the downwash flow of the rotor, and the main lift effect is borne by the rotor in the final stage of tilting.