In order to break through the detection accuracy of the piezoelectric rain sensor in terms of the particle size of small raindrops, this paper proposes a new type of transducer design structure. The peripheral structure of piezoelectric bimorph is added around the traditional transducer structure. Through the ANSYS transient analysis method, a series of simulation analyses on the voltage at different impact positions of the central arc structure, peripheral piezoelectric bimorph, piezoelectric fiber composite material and the piezoelectric fiber composite bimorph are carried out. At the same time, the impedance characteristics of the piezoelectric fiber composites bimorph caused by different water film thicknesses are simulated and analyzed, and finally the effectiveness of the simulated structure is verified. The results show that this research plays a certain supporting role in improving the sensitivity of raindrop detection and realizing the key technology breakthrough of the new rain sensor.