Among the MEMS field, the design and simulation of piezoelectric micro-actuators are difficult as compared to thermal micro-actuators and electrostatic micro-actuators. The main reason of the piezo-electric material coupling effect is difficult to calculate. However the piezo-electric material has several advantages and characteristics for designing micro-actuators. Moreover, the design is usually done by the experimental or try-and-error method which is not so effective. It should be noted that there is not a simple method already developed for the design and simulation of the piezo-electric micro-actuators. In this research we proposed to use the software of ANSYS for the simulation of piezo-electric micro-pump. Simulation of force output of piezo-micro-pump can use ANSYS software to establish the simulation system of piezo-micro-pump. The micro-pump will have different resonance frequency, back-pressure and fluid due to piezo-electric characteristic. In this study, the author used a square, rectangle and circle geometric shape to simulate the result, each geometric shape has four different kinds of size. As a result, there are twelve groups of different simulation results. We are able to using the chart to present and explain the relation between resonance frequency and displacement.