Offshore wind farm high humidity environment as the background, hypothesis of moist air is a mixture of dry air and small droplets, using Euler wall film model calculation of rotating three-dimensional wind turbine blade aerodynamic characteristics, analyses emphatically the influence of moisture on the aerodynamic performance of blade and the distribution of water droplets at blade surface under the condition of three-dimensional rotation. The study found that, with the increase of humidity, the blade power and thrust decreases. The main effect of moisture on the friction of blade surface, in comparison, the impact of pressure on the blade surface is small. By calculating the blade surface droplet collection efficiency at various conditions, it is helpful to prevent the wind turbine blades from the ice and remove the ice. Furthermore, understanding the location of droplets/particles collision the blade surface at various conditions is helpful to the blade manufacturers or the wind farm owner to have the targeted protection blade.