A closer to the actual model of milling cutter structure and threedimensional (3D) milling with finite element method (FEM) was established. The process of highspeed milling titanium alloy Ti6Al4V was simulated, analyzing the distribution of surface residual stress under different conditions of tool parameters and cutting parameters, and obtaining the basic influence rules of various factors on residual stresses was obtained. The results indicate the rules that the tensile residual stress in the surface of the workpiece is rapidly transformed into compressive stress, whose maximum value is found between 100~200 μm. The residual stress on machined surface is decreased with the increasing of the tool rake angle, cutting speed and feed per tooth. The cutting depth has little influence on the surface residual stress of workpiece.