In order to obtain a portable and simple vibration energy harvester and overcome the problem of low output of traditional energy harvesters, a double-L bracket kickback piezoelectric energy harvester was proposed, which combined the nonlinear characteristics of the tensile structure with piezoelectric technology, which could effectively improve the dynamic response and output performance of the energy harvester. The effects of external resistance, magnetic distance, excitation acceleration and angle on the output performance of the harvester were analyzed. The experimental results show that the output power reaches the peak value of the harvester at the optimal external resistance value, and the optimal external resistance value is 200 kΩ. The introduction of magnetic force can significantly improve the output performance of the energy harvester. At a magnetic distance of 18 mm, the harvester captures the most energy, and its optimal output performance reaches 1.12 mW at 12.1 Hz. In addition, the excitation acceleration has an obvious impact on the output characteristics of the energy harvesting system, and the output voltage and output power of the energy harvester also increase with the larger the excitation acceleration, and the maximum output power of the energy harvesting system reaches 1.39 mW under the condition of the excited acceleration of 0.4 g and the frequency of 12 Hz. The harvester has good output voltage and output power in the angle range of 0°~45°, and has the advantage of working under the condition of uncertain excitation direction. Practical application experiments further prove that the energy harvester can continuously output a large and stable voltage, which provides an effective solution to solve the problem of low output of traditional energy harvester.