Nonlinear vibration energy harvesting represents a critical approach for achieving a bandwidth energy harvester. Difficulties in obtaining high-energy output for nonlinear energy harvesters become a huge obstacle in their practical applications. Recently reported strategies based on imparting external mechanical or electrical impacts have been verified to be promising for solutions. However, it is not demonstrated in experiment whether these strategies are suitable in the typical buckled-bridge nonlinear vibration energy harvesters. In this letter, we propose a buckled-bridge piezoelectric energy harvester to verify the feasibility of these strategies. The harvester is mainly consisted of a flexible piezoelectric buckled bridge. A bulked-bridge piezoelectric energy harvesting is analyzed in theory. Through modifying the theoretical model, the external impacts are introduced in theory. The fabricated harvester can reach the maximum output peak open-circuit voltage of 14.1 V (upward) or 9.6 V (downward) at the applied accelerations of 0.8 g. The obtained high-energy output has a big phase difference from the low-energy output. Meanwhile, the output voltage is not a perfect trigonometric function signal as the excited acceleration by the large inter-well oscillations.