A driving circuit for providing a driving voltage to a first flash light-emitting diode is provided. The driving circuit includes an inductor, a first switch, a second switch, a capacitor, a third switch, a fourth switch and a control unit. The control unit controls operating modes of the inductor and the capacitor to a boost mode or a buck mode according to a driving mode of the first flash light-emitting diode, and determines whether to switch the operating modes of the inductor and the capacitor according to a first driving current flowing through the first flash light-emitting diode. An operating method for the driving circuit is also provided.