At present, the lack of the optimal cutting parameters of high speed milling is the obstacle to its widely application. In this paper, the simplified and rapid optimization method is proposed on high speed milling alloy thin-walled workpiece. The normal selection method of cutting tools and cutting conditions is put forward as the precondition of parameter optimization. The acquirement method of optimal parameters is presented. The maximal critical axial depths of cut at the different cutting conditions are achieved according to chatter stability theory. The materials removal rate is selected as the optimal objective. The optimal parameters are filtrated up and validated according to the constraint conditions including machining tool, cutting tools, surface quality and precision of the parts.