Through UG modeling,parameter calculation and path simulation,the parameters were optimized for the 660MW cylinder pattern design process.Five-axis CNC milling machine and suitable tools were selected for integrated processing of the cylinder pattern.Through optimizing tool path,the product geometric parameters are fully met the requirements of the design drawings,the appearance is good.After block processing,the assembly quality is stable and reliable.Compared to the traditional processing mode,the products produced failure rate is decreased about 90%,processing efficiency is increased about 50%.Improving the processing efficiency and surface quality,this program provides reference for other large-scale processing.