A driving system includes a voltage conversion module, a frequency control module, a voltage switching module and a detecting module. The voltage conversion module is used for converting a first DC voltage into a second DC voltage. The frequency control module searches a resonant working frequency of a piezoelectric actuator through circuit oscillation and generates a switching signal according to the resonant working frequency. According to the switching signal, the voltage switching module converts the second DC voltage into an AC voltage so as to drive the piezoelectric actuator. The detecting module includes a gas pressure sensor and a microcontroller. The gas pressure sensor generates a detected gas pressure value according to a result of detecting a gas pressure of the piezoelectric pump. The microcontroller controls the voltage conversion module to adjust the output voltage. Consequently, the gas pressure of the piezoelectric pump is adjusted.