Multi-layer piezoelectric device

The utility model relates to a multi-layer piezoelectric device used inside an asphalt concrete pavement. The multi-layer piezoelectric device comprises a plurality of cylinder-shaped layered piezoelectric transducers, a metal mold and a packaging protection layer; each layered piezoelectric transducer comprises a piezoelectric element, a pre-stress screw bolt, a front metal cover plate and a rear metal cover plate; each layered piezoelectric transducer is arranged in the metal mold in a fixed manner, the front metal cover plate of the layered piezoelectric transducer is exposed out of the upper surface of the metal mold, all the layered piezoelectric transducers are connected in parallel, and the packaging protection layer fills gaps between the metal molds and the layered piezoelectric transducers and covers the upper surface of the metal mold. The multi-layer piezoelectric device of the utility model can be used for converting external force and vibration applied on the asphalt concrete pavement into electric energy, the compatibility of the layered piezoelectric transducers and asphalt concretes can be improved, and damage caused to an asphalt concrete structure is small.