In order to realize the selfwalking of a microintelligent machine, a micromachine driven by piezoelectric structure is designed. The mechanical vibration, piezoelectric coupling and walking speed of the structure are studied. Firstly, the 3D model of mechanical structures is established according to the need of selfwalking motion. Then, the modal analysis of mechanical structure is carried out to find out the elongation mode, bending mode and torsion mode needed for selfwalking. Secondly, in order to make the three modes of coupled resonance walk, it is necessary to continuously optimize the size of the mechanical structure to make the three modal frequencies as close as possible and make the modes more resonant. Finally, the actual object is processed according to the model, and the experimental test is carried out. Through different frequency excitation and comparison of the speed obtained, the optimal frequency for the selfwalking of the micromachine is found out. The experimental results show that under the excitation of 21.5 kHz frequency, the micromachine can walk at the maximum speed of 8.8×10-2 μm/s. It basically meets the requirements of stability and controllability of microintelligent machines.