基于Timoshenko梁弯曲理论，该文建立了双激励阶梯形弯曲振动夹心式压电换能器的传递矩阵理论模型。利用解析理论模型和有限元仿真对换能器的前4阶弯曲振动特性进行了计算分析。结果表明，在换能器的各阶弯曲振动模态下，解析理论计算与有限元仿真均取得了一致结果，即在低阶(一、二阶)弯曲振动模式下换能器有效机电耦合系数大，高阶弯曲振动模式下换能器的有效机电耦合系数小。阶梯形前盖板的直径比对换能器的各阶弯曲共振频率和放大系数均有较大的影响，直径比越大，弯曲共振频率越低，放大系数越大。

Based on the flexural beam theory proposed by Timoshenko, this paper establishes a transfer matrix theory of the dual excitation stepped sandwich piezoelectric transducer in flexural vibration, The analytical theoretical model and FE simulation are used to calculate and analyze the first four order flexural vibration characteristics of the transducer, The results of the analytical theoretical calculation and the FE simulation are consistent in all flexural vibration modes of the transducer, The effective electromechanical coupling coefficient of the transducer is large in low order (first and second order) flexural vibration mode, and small in high order flexural vibration mode, The diameter ratio of the stepped front cover has a greater impact on the flexural resonance frequency and the amplification factor of the transducer, the larger the diameter ratio, the lower the flexural resonance frequency and the greater the amplification factor,