Milling temperature directly affects surface integrity and fatigue life, which is one of the important physical parameters in the process of machining. At present, the prediction of cutting temperature is mainly focusing on orthogonal cutting and turning; there is little research on the prediction of milling temperature of workpiece. The main idea is to discretize the cutting time and heat source, which is learning from the idea of milling force modeling. The moving heat source method is used to predict the workpiece temperature rise in milling process. The geometric kinematics of five-axis machining motion is analyzed. The temperature rise contribution can be calculated in the shear zone based on orthogonal cutting model through coordinate transformation. The proposed model is verified by experiments and 4-axis milling of cylinder surface temperature field is analyzed by simulation. This method can be extended to the temperature prediction of other processing methods, such as five-axis machining and turn-milling compound machining.