The working speed of supercharger is extremely high and hence a sharp rise of speed at operation is thoroughly possible. If the impeller is broken, it will cause disastrous consequence to supercharger. So it is of great significance to obtain the maximum failure speed of compressor impeller by numerical simulation in the early stage of product development. The tensile test of 2A70 impeller material was carried out and the elastic-plastic constitutive model was established to provide material boundary for impeller simulation. Based on the overspeed failure test and simulation of compressor impeller, three kinds of prediction methods for failure speed were proposed based on Mises stress, principal plastic strain and equivalent plastic strain energy and the comparison was conducted. The results showed that the Mises stress method had the highest accuracy and the relative error was 4.2%. The prediction error for equivalent plastic strain energy and principal plastic strain method was 6.9% and 8.8% respectively and it was relatively larger. The maximum failure speeds for all the three prediction methods were slightly large.