The ANSYS model of piezoelectric cantilever beam generator is established by ANSYS finite element simulation software, and the modal analysis and harmonic response analysis are carried out.When the acceleration is 0.015 m/s2 and the mass is in different positions, the variation of the open circuit voltage of the output of the piezoelectric vibrator with frequency is simulated and analyzed. The simulation results show that the maximum open circuit voltage of the device is 19.3 V when the distance between the mass block and the clamping end of the cantilever is 75mm.An experimental plat form has been set up to investigate the output characteristic of the piezoelectric vibratorwhen the mass block is in different positions. The experimental results show that the maximum effective value of the open circuit output voltage of the piezoelectric beam can reach 17.8 V at the firstorder resonant frequency of the acceleration when the mass is 77 mm from the clamping end.When the fullbridge rectifier circuit is connected to the RC circuit and the resistance is 1.3 MΩ, the maximum instantaneous power is 55 μW.The results show that the mass block in a piezoelectric cantilever beam with mass block has an optimal position, which makes the opening voltage and output power maximum.