Because there will be some small gaps between the milling cutter and the tool holder, the tool may vibrate during the machining process. Vibration will make the cutting amount of the cutter's peripheral edge uneven, and the cutting and expanding amount will be larger than the original set value. The result will affect the machining accuracy and tool life. However, when the width of the processed groove is too small, the tool can be effectively vibrated, and the required groove width can be obtained by increasing the cutting and expanding amount. In this case, the larger amplitude of the milling cutter should be below 0.02mm. Otherwise, stable cutting cannot be performed. The smaller the milling cutter vibration in normal machining, the better.