High material removal rates can be obtained by machining at higher axial depth of cut and spindle speeds in highspeed milling process. However, a limitation to machining at higher axial depth of cut is chatter. The dynamic instability of highspeed milling system may cause surface geometric accuracy deviation of machined parts. The analysis of surface position error in highspeed milling plays an important role in characterizing the cutting process, estimating the tool life and optimizing the process. For this purpose, a numerical analysis and experimental method is present without considering the effect of regenerative chatter. Firstly, the schematic model of highspeed milling process is developed. Then the dynamic milling force model is constructed and the analysis method of surface position error is derived. Through numerical analysis combined with milling experiments, the machining stability lobe diagram of highspeed milling is achieved. Furthermore, the surface position error in up milling is studied, and the influence of spindle speed and axial cutting position on surface position error is analyzed detailed. Finally, a comprehensive diagram highspeed milling is described which combines the stability lobe diagram and the surface position error data in the same diagram. The surface position error is predicted and the processing condition is optimized by comprehensive analysis.