Improving the energy-conversion efficiency of triboelectric nanogenerators remains a challenge. The aim of this study is to provide an optimization scheme for a bouncing ball triboelectric nanogenerator (BB-TENG) to efficiently convert vibration energy into electrical energy. In this study, an equivalent electrical model of a BB-TENG was established, and the charge density σ, contact area S, and dielectric layer thickness δ were found to be the main parameters affecting the electrical performance in this model. Furthermore, numerical calculations and experimental investigations were performed to optimize the structure of the BB-TENG. Through optimization, the maximum power density of the BB-TENG increased by 56.0% compared to the original design, the maximum average voltage increased by 61.8%, and the amount of transferred charge increased by 78.6%.