The invention aims at providing an adjustable low-voltage bubble generator which comprises an alternate current to direction current power supply, a capacitor, a slide rheostat, current limit resistors, a protection resistor, alternate current contactors, a voltmeter, a charge switch, a discharge switch, a charge indicator, a discharge indicator and a power supply indicator, wherein an input terminal of the alternate current to direct current power supply is connected with an alternate current socket, the power supply indicator is connected in parallel with an input terminal of the alternate current to direct current power supply, an output terminal of the alternate current to direct current power supply is connected with the current limit resistor, the slide rheostat and another current limit resistor sequentially in series to form a closed loop circuit, the protection resistor, the capacitor and the first alternate current contactor are sequentially connected in series and then are connected with the slide rheostat in parallel to form the charge circuit, and the capacitor is connected with a discharge output terminal and the second alternate current contactor in series to form the discharge circuit. Compared with the prior bubble generator, the adjustable low-voltage bubble generator has the huge advantages on the aspects of operation, repeatability, safety, experimental period and experimental cost.