A switched-capacitor power converting apparatus and an operating method thereof are disclosed. The switched-capacitor power converting apparatus includes an output stage, a determination circuit, a switch control circuit and a voltage regulation circuit. The output stage has an output terminal. The determination circuit is coupled to the output terminal, and generates a mode switching signal according to an output voltage of the output terminal and a reference voltage. The switch control circuit is coupled to the output stage and the determination circuit and controls the output stage to operate in a default voltage mode or an operation mode according to the mode switching signal. The voltage regulation circuit is coupled to the output terminal and the determination circuit and maintains the output voltage of the output terminal at a default value in the default voltage mode.