In order to improve lift/drag of the tiltrotor aircraft in forward flight mode, the airfoil was optimized according to the flow velocity in front of the wing. Using NACA2412 as the original airfoil. Firstly, the airfoil parameterization was carried out by Hicks-Henne method and the design variables was determined; Isight integrated airfoil generation, mesh generation and flow field solver were used to build airfoil automatic optimization platform. Then, in order to improve the efficiency of optimization, a surrogate model based on Optimal Latin Hypercube Design (Opt LHD) and Radial Basis Function (RBF) was adopted, and multi-island genetic algorithm (MIGA) was used to optimize the airfoil. Finally, the optimized airfoil was used to generate wing and the aerodynamic characteristics was calculated. In order to illustrate the effectiveness of the optimization method used in this paper, two optimization results were compared according to the different boundary conditions. In order to reduce the computational complexity, the rotor was replaced by actuator disk with the use of momentum source method. The results show that the lift/drag of the wing was increased by 66.03% in the forward flight mode.