Predicting wind turbine S825 airfoil’s aerodynamic performance is crucial to improving its energy efficiency and reducing its environmental impact. In this paper, a numerical simulation on the wind turbine S825 airfoil is conducted with k-ω turbulence model at different attack angles. By comparing with experimental data, a new method of modifying k-ω model is proposed. A modifying function is proposed to limit the production term in ω equation based on fluid rotation and deformation. This method improves turbulent viscosity and decreases separating region when the airfoil works at large separating conditions. The predictive accuracy could be improved by using the modified k-ω turbulence model. Predicting wind turbine S825 airfoil’s aerodynamic performance is crucial to improving its energy efficiency and reducing its environmental impact. In this paper, a numerical simulation on the wind turbine S825 airfoil is conducted with k-ω turbulence model at different attack angles. data, a new method of modifying k-ω model is proposed. A modifying function is proposed to limit the production term in ω equation based on fluid rotation and deformation. This method improves turbulent viscosity and reducing separating region when the airfoil works at large separating The predictive accuracy could be improved by using the modified k-ω turbulence model.