The present disclosure discloses a charging device, which comprises an energy storage module, an output interface, a detection unit, a switch module, a control module, and a capacitor. The output interface is configured to be electrically coupled to a load. The detection unit detects electrical parameters of the load and the energy storage module. The switch module is electrically coupled between the energy storage module and the output interface. When the load is electrically coupled to the output interface, the control module turns on the switch module based on the electrical parameters of the load and the energy storage module, to switch on an electrical connection between the energy storage module and the output interface. The capacitor is configured to keep the switch module in an on state steadily when the control module turns on the switch module. The present disclosure also discloses an emergency starting method.