Cutting force model for flat end milling and dynamic model of cam milling system were established based on the analysis of machining system for parallel indexing cam contour milling. Solution for dynamic performance of this kind of milling system has been introduced. A system, consisting of NC milling machine SK1632K3, tooling and workpiece, has been taken as example to analyze how cutting speed, feeding, or processing redundancy influence the dynamic performance of machining system. Furthermore, milling error of cam contour has been evaluated corresponding to different machining parameters. Simulation and analysis results are very close to practical manufacturing situation.