Abstract: The relaxed ferroelectric single crystal material PIMNT is a new material with a higher electro-mechanical coupling coefficient and better piezoelectric performance than conventional PZT materials. Its piezoelectric coefficient is 6 times higher than that of ceramic materials, and its strain is more than 10 times higher than that of piezoelectric ceramics. In this paper, the PIMNT piezoelectric single crystal material is applied to the bender transducer with an air cavity, and the ANSYS simulation software is used to optimize the transducer structure and determine the transducer size. A PIMNT piezoelectric single crystal transducer and a PZT4 piezoelectric ceramic transducer are made, and the measurements are performed in the pool. The measured results of the transducers are consistent with the simulation results. The measured center frequency of the PIMNT single crystal transducer is 2.85 kHz and the maximal transmitting voltage response can reach 136.3dB. The results show that compared with ceramic transducers of the same size, the application of PIMNT piezoelectric single crystal material to bender transducers can reduce the resonant frequency and improve the transmitting voltage response and the transducer operating performance. It provides a reference for further improving the comprehensive performance of single crystal transducer.