Abstract: To solve the problems of low efficiency and low precision of traditional hand grinding for wind turbine blades surface,a sand blasting process was proposed. The movement rules of fluid and particles and the influence of sandblasting parameters on the surface morphology of blades were studied by the method of combining the numerical calculation and experiments. Firstly,based on the theory of fluid mechanics and Newton’s second law,the numerical simulation of spraying process was established to obtain the motion law of spraying fluid and particles. Then the formation mechanism of blade’s micro-morphology under different sand blasting parameters was analyzed by scanning electron microscopy. The on-site test show that the optimum parameters of sand blasting keeping the uniform velocity of air and particles in nozzle were spray pressure 0.7 MPa,nozzle length 0.5 m and the spray paint surface met the minimum suction requirement of 8 MPa. Furthermore,conclusions can be drawn that the adhesion of the spray paint surface and uniformity were mainly affected by the spray pressure and particles diameter respectively.