The factors affecting the machining accuracy of magnets have a great relationship with the processing equipment, tools and processing technology, and the technical level of the operator. In addition, the microstructure of the material also has a great influence on the machining accuracy of the magnet. For example, magnets with coarse main phase grains are prone to pitting on the surface of the machined state; magnets with abnormally grown internal grains are prone to ant pits on the surface of the machined state; magnets with uneven density, composition and orientation degree, The size of the chamfer is uneven; the magnet with high oxygen content is brittle, and it is prone to chipping and falling corners during the machining process; the magnet with the coarse grain of the main phase and the uneven distribution of Nd-rich phase has a uniform bonding force between the electroplating layer and the substrate , The uniformity of the coating thickness and the corrosion resistance of the coating will be worse than the magnets with fine grains of the main phase and uniform distribution of the Nd-rich phase. In order to obtain sintered Nd-Fe-B magnet products with high geometric accuracy, it is necessary to fully communicate and cooperate with material manufacturing engineers, machining engineers and users.