This article presents the dynamic modeling of a bimodal piezoelectric ceramic motor by use of the finite element method. The extended Hamilton's principle is utilized for formulating dynamic equation of motion, and the Lagrange multiplier method is used to model the contact dynamics between the resonator beam tip and the rotor. The numerical simulation result is approximate to the practical experimental data, which indicates that the modeling and the experiment are fairly accurate. The Taguchi experimental design method is applied to decrease the experimental effort and find the optimal design. This approach shows that the shape of the output head of the motor determines the output performance significantly. The modified shapes of output head also are carried out with a practical experiment to verify the outcomes based on the Taguchi experimental design method.