Obtaining energy from human body activities to power electronic equipment has broad application prospects. In this study, a piezoelectric energy harvesting system is designed to harvest energy from human finger rapping. The harvested energy can drive a laser lamp group to operate. The piezoelectric energy harvester uses a piezoelectric cantilever beam with a spring-mass block at the free end to obtain the kinetic energy of the finger operating a laser pen. The structure can produce considerable bending deformation under finger movement. At the same time, a dual-input synchronized switch harvesting on inductor circuit is designed to extract the charge generated by the piezoelectric beam when the spring-mass block at the free end is rapped and store it in the energy storage element. The charge and discharge of the energy storage element are controlled by a DC-DC management circuit. Experimental results show that the average harvesting power of the piezoelectric energy acquisition system is 169 μW, and its power density is 388.5 μW/cm3. When the spring-mass block is rapped for 8 s, the energy generated by the piezoelectric energy harvester lights the laser pen for 0.35 s.