In order to explore the influence of the change of wet salt spray environment on the aerodynamic performance of the offshore wind airfoil, the component transport model and discrete phase model were used to establish the environmental model and set the parameters of the offshore salt spray environment. Combined with the user-defined function of the wall deposition model, the numerical simulation was carried out on the NACA4415 airfoil. It is found that the lift resistance coefficient of airfoil increases with the increase of salt spray concentration and decreases with the increase of air humidity. The particles are evenly distributed on the surface of the airfoil at 0.2~0.8 chord, with less deposition near the leading edge and more deposition at the trailing edge. With the increase of velocity, the deposition rate of particles decreases. With the increase of airfoil attack angle, the surface velocity distribution changes and the deposition rate is affected. With the increase of air humidity, the deposition amount of salt spray particles on the airfoil surface is reduced, and the decrease is more obvious in the area with large deposition amount, and the influence of humidity decreases with the increase of the angle of attack.