Disclosed is a piezoelectric energy harvesting apparatus. The piezoelectric energy harvesting apparatus includes: a piezoelectric energy harvesting array that includes a plurality of piezoelectric energy harvesting devices converting an external vibration into electric energy; a plurality of switches that is connected in series to the piezoelectric energy harvesting devices, respectively, and fits the resonance frequency of the piezoelectric energy harvesting array to the frequency of the external vibration by adjusting the resonance frequencies of the piezoelectric energy harvesting devices through the operation of the switches; and at least one or more rectifiers that convert alternating voltage outputted from the piezoelectric energy harvesting array into direct voltage.