Abstract: A kind of Janus-Ring transducer with two piezoelectric rings placed in a certain distance around a Janus driver is presented.Rings have radial vibration,Janus has a longitudinal vibration,with the resonance of Helmholtz cavity between Rings and Janus.The three resonances coupling widen the working frequency bandwidth of transducer.The performances are simulated by the means of finite element method.The prototype is fabricated and tested.The frequency band is from 1.8 kHz to 8.0 kHz.The max transmitting voltage response is 144 dB.And contrast to the typical Janus-Helmholtz transducer,Janus-Ring transducer has the characteristic of wider bandwidth,greater transmitting voltage response,less fluctuations of transmitting voltage response in working frequency band.