Abstract: A kind of circular ring high frequency wide band underwater acoustic transducer is developed, By using the Low Q value and broadband characteristics of the piezoelectricity composite material, and the dual mode coupling is used to broaden the bandwidth of the transducer by double ring stacking along the axial direction. Through theoretical analysis and simulation calculation, the geometric dimensions of the sensitive components are determined. By cutting piezoelectric ceramics-filling the flexible polymer-coating electrode the piezoelectric composite rings are processed. And then the stack sensitive element can be made by stacking two piezoelectric composite rings with the same outer diameter and different thickness in axial direction. Finally, the transducer can be made by pouring waterproof permeable, the performance of transducer has also been tested in the water and the test results show that the resonant frequency is 410 kHz, the maximum transmit voltage response is 150 dB, the -3 dB bandwidth can reaches 60 kHz, the horizontal direetivity (-5 dB) is 360°, and the vertical direetivity (-3 dB) is 20°. It is shown that the bandwidth of the transducer can be enlarged remarkably by using the method of stacking two different thickness piezoelectric composite rings along the axial direction, And the horizontal omnidirectional emission of acoustic wave can be realized.