A piezoelectric printhead was designed and fabricated for Drop-On-Demand(DOD)printing. The formation of a droplet was captured by a CCD camera in the jetting experiment on a droplet jetting platform. The deformation curve of a piezoelectric plate was measured by a laser displacement sensor and it then was inputted into a flow simulation solver to simulate the process of droplet jetting with the methodology of free surface volume of fluid. The results show that the formation time , size and the volume and speed of the droplet simulated are in agreement with that of experiments. In the contrast between the formation process of droplet and the displacement curve of piezoelectric plate, it is found that the main droplet has dripped off the nozzle before the end of a high voltage, which can be used to improve the maximum frequency of droplet jetting by reducing the high voltage time and increasing the damping vibration resistance value of piezoelectric plate. The simulation of droplet jetting can also explain the formation mechanism of additional droplets in the experiment, and can successfully reduce the additional droplet by changing the structure of printhead and the viscosity of forming materials.