Abstract: In view of the problem that piezoelectric ceramic plate of cantilever PZT piezoelectric energy harvester may crack or rupture under cyclic vibration, the scheme of magnetic force limiting structure was developed. Harmonic response analysis for the original structure and limiting structure by ANSYS showed that the scheme effectively reduced the maximum stress in the structure. Finally, optimization for the magnetic force limiting scheme was done, and the results of simulation prove that the optimized structure can not only ensure optimum of harvesting energy, but also effectively control fatigue fracture of the piezoelectric ceramic plate.