Abstract: A wind tunnel test and numerical simulation of aerodynamic interference in hover are carried out for tiltrotor aircraft. In the test, the rotor lift, torque and aerodynamic force of half model wing are measured. At the same time, the moving overset grids method is used to numerically simulate the two states of Isorotor, wing angle of attack 0° and 90°, by solving the N-S equation. The correlation between numerical simulation and wind tunnel test is carried out to verify the effectiveness of the numerical simulation method. The results show that when the aerodynamic force of fuselage is not considered, the difference of rotor aerodynamic characteristics is not obvious under the three states; when the aerodynamic force of fuselage is considered, in the wing angle of attack 0° state, the fuselage generates about 18.2% downward load, the single blade and fuselage have strong unsteady aerodynamic characteristics, in which the ratio of dynamic value to average value of single blade lift coefficient is 9.8%, and the ratio of dynamic value to average value of fuselage lift coefficient is 18.38%.