The work aims to determine the appropriate driving waveform by studying the effect of time parameter and voltage amplitude of bipolar trapezoidal wave on droplet injection, aiming to avoid the appearance of satellite droplet and improve the velocity of droplet injection by piezoelectric inkjet printing head. The piezoelectric inkjet process was simulated and analyzed by ANSYS Workbench platform. The piezoelectric-elastic-fluid bidirectional fluid-structure coupling model and two-phase flow model were subject to distribution structure analysis. The driving waveform was optimized according to droplet state and injection velocity. The time parameters of the bipolar trapezoidal wave were determined as 4, 14, 4, 20 and 4 μs, and the voltage amplitude was 15 V and 35 V. When the driving waveform was loaded, the average droplet injection velocity was 3.1 m/s and the droplet state was good without satellite droplet. The time parameters and voltage amplitudes of the driving waveform have a certain effect on the velocity of droplet injection and the control of satellite droplets. The quality of droplet injection by the piezoelectric inkjet printing head can be improved through the optimization of driving waveform.