Compared with traditional configuration tiltrotor aircraft， tilting wing and rotor UAV can significantly reduce the aerodynamic interference of rotor wake on wings in hover， and increase flight efficiency. Regarding the continuous tilting transition process of the UAV with complex unsteady aerodynamic characteristics， the delayed detached eddy simulation （DDES） method， improved from the classical detached eddy simulation （DES） method， is used to simulate aerodynamic interference. During the tilting transition process， the aircraft's forward flight speed， rotor pitch angle， fuselage and fixed wing angle of attack， and nacelle inclination angle all dynamically change over time. By comparing with the traditional configuration， the aerodynamic performance changes and flow field mechanisms during the tilting transition process are analyzed. The simulation calculation results show that the UAV in the initial state of tilting is less affected by the rotor downwash. During the tilting process before the 30° nacelle inclination angle， due to the increased resistance of the tilting wing segment， the required thrust of the rotor are increased. The separation vortices generate during the tilting process of the tilting wing section collide with the downwash wake of the rotor， resulting in a larger wake interference area at the wing tip position and a downwash effect on the inner fixed wing tip， reducing the overall lift of the aircraft.