n order to investigate the dynamics of the tri-stable piezoelectric vibration energy harvester (TPVEH), a TPVEH composed of a piezoelectric cantilevered beam with a tip magnet and two external magnets is presented. The magnetic coupling model is established to calculate the nonlinear pulse force between the tip magnet and the two external magnets with the magnetic point dipole model, and then the lumped-parameter dynamics model of the TPVEH is consequently established with force balance principle and Kichihoff current method. The influences of the distances between the tip magnet and the external magnets, the exciting amplitude and frequency on the dynamic characteristics of the TPVEH are analyzed respectively. Finally, a prototype TPVEH is developed and an experimental platform was setup to validate the simulation results. The research results show that the TPVEH will exhibit mono-, bi-and tri-stable motion with the increasing of the exciting amplitude, and the frequency-band, the output performances of the TPVEH obtained from the tri-stable motion are larger than those of the mono- and bi-stable motions.