The tiltrotor UAV has both hovering and vertical takeoff and landing capabilities in the air， as well as high speed cruise performance. Aiming at the problem that the rigid aerodynamic shape of a tiltrotor UAV cannot accurately simulate the real flight performance due to the structural deformation of the elastic material， a CFD/CSD coupling method combining rotor bi-directional loose coupling and wing unidirectional coupling is proposed to numerically simulate the aeroelastic problem of tiltrotor UAV in hover state. Using aeroelastic tailoring to optimize the composite layer of the blade， the maximum deformation displacement of the blade is reduced from 22.34 mm to 17.1 mm， and the hovering efficiency is improved from 69.95% to 72.69%. Computational simulations are conducted on the entire aircraft flow field， and the results show that after considering structural elastic deformation， the increase in thrust generated by the entire aircraft rotor system compared to the individual rotor system decreases from 2.09% to 1.18%. The high-pressure zone generated by the rotor downwash on the deformed wing surface shifts approximately 0.1m towards the wing tip direction compared to the undeformed wing.