In precision parts processing, the path of the tool position relative to the movement of the part is called the processing path. The processing routes are as follows. Hole processing route: The hole processing route refers to the distance between the tool tip position and the upper surface of the hole when the tool is switched from fast forward to work during the hole processing. The machining route of the hole system with high mutual position accuracy. For the hole system processing with high position accuracy, special attention should be paid to the arrangement of the hole processing sequence to avoid bringing in the direction gap of the coordinate axis and affecting the position accuracy. Contour washing processing route: When using the side edge of the end mill to wash the contour parts, in order to reduce the traces of the tool and ensure the surface quality of the parts, the cutting-in and cutting-out points of the milling cutter should follow the contour curve of the part during the processing of precision parts. The tangential cutting of the extension line cuts into and out of the surface of the part, instead of directly cutting into the part along the normal direction of the contour curve of the part, to avoid knife marks on the machined surface and ensure the contour of the part is smooth. Principles of Precision Parts Processing Route The processing route of the groove type workpiece: There are three cutting methods for processing grooves, namely, the line cutting method, the ring cutting method and the first cutting method and the last ring cutting method. The above three are the three workpiece processing routes used in precision parts processing.