Method and device for processing undervoltage protection circuit, and undervoltage protection system

The invention provides a method and a device for processing an undervoltage protection circuit, and an undervoltage protection system. The method comprises: detecting level of current input voltage of an undervoltage protection circuit; shielding a voltage undervoltage protection function of the undervoltage protection circuit on other levels, wherein other levels are different from the level of the current input voltage. Using the above technical scheme, a problem in a related technology that an undervoltage protection function cannot operate under various DC bus voltage, so as to achieve effect that a single board or a secondary power supply module can adapt to different input voltage.