Abstract: In order to eliminate artificial choosing empirical parameters' influence on numerical simulation, the Schnerr-Sauer cavitation model, considering the effect of non-condensable gas, was modified based on the local flow properties. Choosing Mixture multiphase model and Realizable <i<k-ε</i< turbulence model, the numerical simulation was carried out for steady cavitating flows over a 2D NACA0009 MOD hydrofoil by means of the modified and original Schnerr-Sauer model with the cavitation number 0.75 to 0.90,and the simulation results were compared with experimental data. The results show that, for the Schnerr-Sauer cavitation model, considering the effect of non-condensable gas, the density <i<n</i< of non-condensable gas has a great influence on the simulation results before modifying, while the diameter <i<d</i<<sub<nuc</sub< has little influence. The modified cavitation model which considers local shear strain rate can effectively eliminate the obvious effect of the empirical parameters and can improve the accuracy of numerical simulation. The saltation location of cavitation pressure gradient can be accurately predicted by the modified model.