Reynolds number has a great impact on the performance of the scale model which is smaller than the original wind turbine. In this paper, three-dimensional numerical simulation by using the software FLUENT was applied to obtain the aerodynamic performances of the scale model. A prediction of Reynolds number impact on the scale model was presented and the results agreed well with the conclusion of a two-dimensional airfoil research. Finally a correction method of Reynolds number impact was given to conduct the correction of the wind tunnel test.