To suppress the multi mode coupling effect and improve the electro acoustic conversion efficiency of a lens focused transducer made of the piezoelectric ceramic material,a novel lens focused transducer using 1 3 piezoelectric composites is designed in this work.First, the thickness resonant frequency ft and thickness electro mechanical coupling coefficient kt of the 1 3 piezoelectric composites were calculated and simulated,the difference between the theoretical value and the simulation value for ft and kt are 2.947% and 0.933% respectively.Next,the vibration condition of the transducer was analyzed.At the resonant frequency ft of the transducer,the displacement amplitude at radial direction of the acoustic lens center is only 7.9% of the thickness direction,which shows that the radial vibration has been suppressed effectively, and thus the electro acoustic conversion efficiency of transducer has been improved. This study could be used as reference in the development work on focused transducers.