Abstract: In response to the widespread issue of low-frequency vibration control in the environment, a novel two-dimensional three-component locally resonant phononic crystal structure is designed.A perfect phononic crystal structure is modified by replacing one unit cell with a piezoelectric material to create a point defect structure.The energy localization characteristics of the defect band are simulated using the finite element method, and the effects of supercell size and defect position on energy harvesting performance are investigated.The research indicates that introducing a locally resonant phononic crystal structure into the energy harvesting system can significantly enhance its energy harvesting performance.When the size of the supercell structure meets sufficient periodicity, the vibrational energy harvested from defect states gradually stabilizes and reaches a maximum value.Within a given supercell structure, there exists an optimal defect position that maximizes the system’s vibrational energy harvesting performance.For the optimal 5×7 supercell structure, the maximum peak-to-peak voltage generated at 252.9 Hz is 243.5 mV,which is 380 times higher than the output voltage of 0.64 mV produced by an epoxy resin bare board structure of the same size at the same frequency.These research findings provide theoretical references for the manipulation of low-frequency elastic waves and self-powering of low-power instruments.