s：Vertical milling is often adopted in manufacturing of complex curved surfaces such as thin-walled blades used in the air navigation industry. In order to improve the machining efficiency and surface quality. The contact between tool and workpiece was always increased. But the cutter structure parameter is very important for milling stability. The influencing factors in the process of vertical milling cutter was analyzed in this paper. The equation of milling force is established. AdvantEdge FEM software was used for finite element simulation of milling. The milling force, machining deformation, stress and strain are analyzed with the consideration of spiral Angle, diameter and the number of milling cutter blade. The analysis provides a theoretical basis for further study on vibration analysis of line contact milling and tool optimization design.