Abstract: This paper studies the many processing characteristics of radiator parts, high position accuracy and easy deformation Investigate it.According to the structural characteristics of the parts, the machining difficulties are analyzed, the reasonable machining technology is worked out, and the CAM technology is used for NC programming; A special fixture with high positioning accuracy, which can restrain deformation and convenient clamping is designed to calculate the milling force at the thin wall of the parts, physical simulation technology is used to analyze and compare the deformation of the parts fixed by the traditional tooling plate and the special fixture under the same cutting force; The geometric simulation technique is used to process and measure the accuracy of this part; Finally, actual machining and precision measurement are carried out, the experimental results show that the parts achieve a high machining precision.