Power supply voltage stabilizing method and device for mains supply flash and direct-current power supply

The invention is suitable for the technical field of power supplies, and provides a power supply voltage stabilizing method and device for mains supply flash and a direct current power supply. The method comprises the steps of obtaining a mains supply voltage inputted into an AC/DC module; if the duration that the mains supply voltage is smaller than a preset voltage value reaches the first preset time, judging that the mains supply flashes; and increasing a proportional parameter of a PID controller in a control loop of a converter module during the flashing of the commercial power so as to reduce an output voltage drop value of the converter module during the flashing of the commercial power. According to the scheme, the problem of sudden voltage drop at the commercial power flash-off stage can be avoided, and the output voltage drop value is reduced by increasing the proportion parameter, so that the stability of the output voltage of the power supply at the commercial power flash-off stage is ensured. 本发明