In order to obtain the Johnson-Cook（J-C） constitutive parameters that can exactly reflect the plastic flow behavior of the workpiece material under the coupling effect of high temperature, high strain rate and large deformation occurred in high-speed cutting, and make it to suitable for the high-speed cutting simulation. The J-C parameters of Ti-6 Al-4 V was optimized with using the response surface approximation and multi-objective optimization methods to apply it to high-speed cutting simulation. Results show that the optimized constitutive parameters could describe the plastic flow behavior of the workpiece material accurately in a wide range of cutting speeds, and the simulated chip morphologies and the average cutting forces are in good agreement with the experimental results.