The working frequency band width of piezoelectric vibrator is a key index that affects the efficiency of piezoelectric vibratory energy collector. In this paper, the modal frequency of an array piezoelectric vibration energy collector is analyzed, which can be used as a reference for the dynamic design of piezoelectric vibrators. Firstly, based on the vibration theory of the elastic beam, the dynamic equations of the saw-tooth piezoelectric beam are derived, and the factors affecting the modal frequency are analyzed. Then, the finite element model of the saw-tooth piezoelectric beam is established by COMSOL, and its frequency response, power and load impedance matching characteristic and acceleration dependence are analyzed. Finally, the voltage amplitude-frequency characteristic curve of the saw-tooth piezoelectric beam is tested by experimental research, which verifies the rationality of the theoretical analysis and simulation results. The results show that the saw-tooth array piezoelectric vibration energy collector can effectively broaden the working frequency band and improve the power generation efficiency.