In view of the problems existing in the processing of side wall structural parts of high-speed railway trains, the research on high-speed and high-precision numerical control technology of aluminum alloy key parts was carried out on the basis of existing numerical control equipment. According to the structural characteristics and process characteristics of aluminum alloy key parts of high-speed train body, the problems of machining efficiency and accuracy are solved from two aspects of machine tool dynamic characteristics analysis and milling dynamic characteristics software analysis technology and program optimization technology in the process of NC machining of train side wall structure surface. The results show that the technology significantly improves the processing efficiency and quality of key parts, and can be widely used in the same industry.