The parts that support and guide the moving elements to move along the specified trajectory are called guide rail pairs---guide rails. Athletes have linear, circular, and curved trajectories. Rolling circular guides can be incorporated into rolling thrust bearings. Curved guides are rarely used in CNC milling machines. Guide rail is a very important component in machinery, and it also plays a very important role in other lathes such as CNC milling machines. Machining accuracy is directly related to the accuracy of guide rails. For precision machine tools produced in small batches, the workload of guide rail processing accounts for the entire machine tool processing work. In the 40% range of the amount, once the guide rail is abnormal, the maintenance becomes very troublesome. When customers use the CNC milling machine for processing and production, they will definitely encounter the unstable situation of the guide rail accuracy. At this time, the CNC milling machine needs to be repaired in time. During the entire trimming process, we need to pay attention to 3 issues to avoid re-adjusting the guide rail. Injuries are caused, and the CNC milling machine cannot be used normally. Do you know how we should modify the progress of the CNC milling machine guide rail? Consider the mechanical strength of the repair layer itself and the practical operating environment of the guide rail. The standard, performance, and use environment are different, and the repair process should also be used when repairing. Consider whether the selected dressing process has an influence on the accuracy of the guide rail and the mechanical properties. If it is affected by temperature, will it cause deformation of the guide rail, and whether it will change the mechanical strength and surface hardness of the guide rail. Consider the applicability of the selected correction process to the guide rail material. For example, the cast iron material is usually not used for surfacing of the cast iron to the guide rail. Due to the weldability of the cast iron, cracks, pores and other defects are prone to occur, and it is not easy to process it process.