Abstract: An aluminum-based polymer layer of the 1-3 type for making high-frequency underwater acoustic transducers is studied, and its equivalent parameters are calculated. Subsequently, to fabricate the transducer, the equivalent circuit method is used for analysis, and a finite element model is established for simulation to determine the structure and parameters that meet the design requirements. A transducer sample is tested with its underwater transmitting voltage response. Test results show that the transducer operates in the frequency range of 150 kHz to 400 kHz, with a response fluctuation less than 6 dB within the passband, a peak transmitting response of 169.8 dB, a relative bandwidth of 90.9%, and a directivity angle of 6.3° at 300 kHz. The experimental results of this matching layer can serve as a basis for subsequent research on arc-shaped matching layer transducers.