An auxiliary power supply circuit for operating within a wide input voltage range, wherein the auxiliary power supply circuit is configured to be connected to a working voltage conversion circuit of a wide input voltage range direct-current power converter, and comprises: a voltage follower unit comprising: an electronic switch defined as a first electronic switch and comprising: a first terminal configured to be electrically connected to a voltage input terminal of the working voltage conversion circuit; a second terminal configured to be electrically connected to a voltage output terminal of the working voltage conversion circuit; and a control terminal; a resistor electrically connected between the first terminal of the electronic switch and the control terminal of the electronic switch; and a Zener diode having a cathode electrically connected to the control terminal of the electronic switch, wherein a breakdown voltage of the Zener diode is lower than the steady-state output voltage of the working conversion circuit; and characterized by a voltage comparison unit comprising: a comparator having: a non-inverting input terminal deemed as a detecting terminal (V DET) of the voltage comparison unit and configured to be electrically connected to the voltage input terminal of the working voltage conversion circuit; an inverting input terminal receiving a reference voltage (Vref) correlating with a protection voltage higher than the steady-state output voltage of the working conversion circuit; and an output terminal; and a second electronic switch comprising: a first terminal deemed as an output terminal of the voltage comparison unit and electrically connected to the control terminal of the electronic switch; a second terminal provided to be grounded; and a control terminal electrically connected to the output terminal of the comparator. an electronic switch defined as a first electronic switch and comprising: a first terminal configured to be electrically connected to a voltage input terminal of the working voltage conversion circuit; a second terminal configured to be electrically connected to a voltage output terminal of the working voltage conversion circuit; and a control terminal; a first terminal configured to be electrically connected to a voltage input terminal of the working voltage conversion circuit; a second terminal configured to be electrically connected to a voltage output terminal of the working voltage conversion circuit; and a control terminal; a resistor electrically connected between the first terminal of the electronic switch and the control terminal of the electronic switch; and a Zener diode having a cathode electrically connected to the control terminal of the electronic switch, wherein a breakdown voltage of the Zener diode is lower than the steady-state output voltage of the working conversion circuit; and characterized by a voltage comparison unit comprising: a comparator having: a non-inverting input terminal deemed as a detecting terminal (V DET) of the voltage comparison unit and configured to be electrically connected to the voltage input terminal of the working voltage conversion circuit; an inverting input terminal receiving a reference voltage (Vref) correlating with a protection voltage higher than the steady-state output voltage of the working conversion circuit; and an output terminal; and a second electronic switch comprising: a first terminal deemed as an output terminal of the voltage comparison unit and electrically connected to the control terminal of the electronic switch; a second terminal provided to be grounded; and a control terminal electrically connected to the output terminal of the comparator. a comparator having: a non-inverting input terminal deemed as a detecting terminal (V DET) of the voltage comparison unit and configured to be electrically connected to the voltage input terminal of the working voltage conversion circuit; an inverting input terminal receiving a reference voltage (Vref) correlating with a protection voltage higher than the steady-state output voltage of the working conversion circuit; and an output terminal; and a non-inverting input terminal deemed as a detecting terminal (V DET) of the voltage comparison unit and configured to be electrically connected to the voltage input terminal of the working voltage conversion circuit; an inverting input terminal receiving a reference voltage (Vref) correlating with a protection voltage higher than the steady-state output voltage of the working conversion circuit; and an output terminal; and a second electronic switch comprising: a first terminal deemed as an output terminal of the voltage comparison unit and electrically connected to the control terminal of the electronic switch; a second terminal provided to be grounded; and a control terminal electrically connected to the output terminal of the comparator. a first terminal deemed as an output terminal of the voltage comparison unit and electrically connected to the control terminal of the electronic switch; a second terminal provided to be grounded; and a control terminal electrically connected to the output terminal of the comparator.