Abstract: To solve the technical problem that the circular arc Angle of honeycomb core material parts cannot be machined, basing on the principle of ultrasonic machining, an ultrasonic vibration slotting cutter is designed. In order to keeping cutting tools meet the requirements of production, we have analyzed the structural characteristics of the slotting cutter, established a new dynamic model of milling cutter, which is derived by finite element software ABAQUS on the modal analysis of the milling cutter. It has confirmed the rationality of the design by cutter's structure, and provided a perfect structural parameters to support the development of the ultrasonic cutting tool research. The results show that the seventh mode is the ideal mode of the slotting cutter, with regular amplitude distribution and stable vibration. The length of the cutter l=27 mm, the thickness of the cutter t=2.5 mm, and the wedge angle being θ=13°.As the optimal choice of the structure of the slotting cutter, it accords with the requirements of ultrasonic cutting.