These years, the mold has become a very important forming tool in modern industry. And the die steel is the most important technical and material base in mold industry. To obtain the optimized cutting parameters, this paper introduced the cutting performance of WC-Co carbide cutting tools (P10) from cutting force, the surface roughness, chip deformation and the chip-breaking performance in turning 4Cr13 die steel. And the cutting parameters were optimized by homogeneous design method and multiple linear regression analysis method in this paper. The regression models on cutting forces and surface roughness with the cutting parameters were studied and taken the tests of significance. The result showed that it was more suitable for finish turning 4Cr13 die steel using WC-Co carbide tools at vc =183.3m/min, f=0.2mm/r, ap=0.75mm or vc =200m/min, f=0.1mm/r, ap=1mm.