Abstract: The reduction of energy dissipation of rainfall by plants is an important mechanism of soil and water conservation. However, the process of leaves kinetic energy dissipation is not clearly understood due to the lack of suitable observation and measurement device. In order to research the movement process of plant leaves after the impact of raindrops and the change of motion energy of leaves, based on polyvinylidene fluoride (PVDF) piezoelectric film sensor, a device was developed to effectively detect the motion and energy dissipation of leaves after raindrop impingement. The vibration of Ligustrum lucidum leaves under raindrop impingement was measured and the feasibility of the device was verified. On the basis of careful analysis and research on the process of raindrops impingement, the modular independent design of the monitoring device is carried out. The entire monitoring device is composed of three modules: raindrop generation, monitoring capture of leaves movement, and signal collection and processing. The raindrop generation module can be selected according to the actual situation (or can directly measure the natural rainfall). The voltage signal output of the thin film sensing system contains information on raindrops impingement, the splashing of small water droplets and the diffusion of thin water layers. The voltage output of the system is several times to tens of times of the background. There is an obvious linear relationship between the peak value of the voltage and the kinetic energy of raindrops (R²=0.959). The signal frequency domain analysis shows that the system can also effectively capture the vibration signal characteristics of the continuous raindrops impingement on the leaves. For raindrops with different kinetic energy, the coefficient of variation between repetitions is a weak variation of < 10% and a moderate variation of 10%~100%, indicating that the whole device has good system stability. There is an obvious functional relationship between the energy dissipation by the Ligustrum lucidum leaves and the input energy of the raindrop, and the kinetic energy dissipation by the leaves only accounts for about 3%~5% of the initial raindrop kinetic energy, which may be related to the failure to monitor the process of torsion and vibration of the petiole. The device can monitor the movement caused by raindrops impingement on the leaves and the dissipation characteristics of leaves to raindrops, which is beneficial to further understanding of the kinetic energy dissipation mechanism of effect of plants on rainfall.