In a piezo inkjet system, the print head structure, driving waveform, and other factors directly influence the jetting characteristics and printing accuracy. In this study, the numerical simulation software COMSOL was employed to establish a model of piezoelectric inkjet printhead system. The influence of driving parameters— voltage amplitude, voltage residence time, and operating frequency—on jetting characteristics was investigated, specifically droplet velocity and volume. Additionally, a bipolar driving waveform was designed to suppress the residual oscillation. The results demonstrate that the damping waveform effectively suppresses the residual vibration of the pressure wave, significantly improving the working frequency and printing accuracy of the inkjet printhead.