The paper proposes a piezoelectric stack structure based on the rolling depression, which combines the Cymbal piezoelectric transducer and the piezoelectric vibrator stack to convert the reciprocating vibration into an one?way oppression of piezoelectric vibrator using the ball bearing as the excitation source. Using the simulation software, the force on the piezoelectric unit produced by ball and the output voltage and trapped energy of transducer structure in parallel and series mode are examined, and the piezoelectric conversion characteristics of the structure are obtained. The simulation results show that the ball force on the piezoelectric stack does not always decrease with the increase of the number of piezoelectric layers. It increases gradually during 1-5 layers of piezoelectric ceramic, but decreases in the more than 5 layers. Meanwhile, it is found that if the total number of the layers of piezoelectric ceramics is unchanged, the total energy trapped by piezoelectric stack remains the same. However, when the number of layers is less than 5, it decreases with the increase of the number, but it gradually increases when the layers are more than 5.