The invention provides a design method of an ultrasonic elliptic vibration cutting device and belongs to the technical field of precise machining. The design method of the ultrasonic elliptic vibration cutting device comprises the following steps that firstly, the parameters of the ultrasonic elliptic vibration cutting device are determined; secondly, the length of an energy converter is calculated; thirdly, the positions where a wave loop and a wave node are located when the energy converter conducts bending vibration are calculated; fourthly, a piezoelectric ceramic piece is inserted, and the length of the energy converter is corrected; fifthly, the lengths of amplitude-change poles of all the levels are calculated; and sixthly, according to the shape of a cutter, a plane is milled at the tail end of the amplitude-change pole of the last level. According to the design method of the ultrasonic elliptic vibration cutting device, the cutter can generate elliptic movement path on a two-dimensional plane. In addition, in the design method, mathematical formula deduction is adopted, and empirical design and simulating optimization design are avoided.