To increase frequency bands and the applicability in vibration environments, a piezoelectric generator consisted of multi-vibrators was presented. The output performance of the piezoelectric generator connected with vibrators in different methods (direct serial/parallel-connection, serial/parallel-connection with rectifiers) was studied theoretically and experimentally. The research results show that the piezoelectric generators connected with vibrators in serial/parallel through rectifiers achieves higher output voltages and wider frequency bands than those connected with vibrators directly. Moreover, the serial-connection piezoelectric generator takes advantages over the parallel-connection one in output voltages and frequency bands. A piezoelectric generator consisted of three cantilevers was fabricated and tested with the vibrators connected in different ways. With the output voltage beyond 10 V, the individual frequency bands of the three unconnected cantilevers are 143.1-148.1 Hz, 160-166.2 Hz and 173.1-184.3 Hz, respectively. However, the total frequency band for output voltage beyond 10 V is extended to 141.8-190 Hz as the cantilevers are connected in serial with rectifiers.