To address the limitation of single-mode motion in micro piezoelectric robots, this study proposes a piezoe-lectric-driven micro amphibious crawling robot. The robot utilizes the inverse piezoelectric effect of piezoelectric ceramics to excite multiple vibration modes of its body, enabling both terrestrial crawling via contact friction and aquatic swimming via jet flow, thus achieving amphibious locomotion. A compact structure driven by a single-phase excitation signal allows dual-mode motion on land and in water. Finite element modeling was conducted using Ansys 19.0 to analyze the robot's structural design, operating principle, and optimal working modes. A prototype was fabricated and experimentally tested. At a driving frequency of 17.0 kHz and a peak -to -peak voltage of 100 V, the robot achieved a maximum crawling speed of 130 mm/s, equivalent to 6.5 body lengths per second. At 227.0 kHz and the same voltage, its average swimming speed on the water surface reached 50 mm/s, or 2.5 body lengths per second. The consistency between simulation and experimental results verifies the feasibility of the proposed structural design and confirms the validity of the operating principle.