The invention provides an improved voltage-multiplying valley-filling circuit. On the basis of an existing valley-filling circuit, a voltage shift switch is additionally arranged and is connected between an existing valley-filling circuit and an arrangement bridge circuit; during working at a high-voltage segment, namely, the mains specification of a distribution network is within a region of 220VAC, and the improved voltage-multiplying valley-filling circuit can work in a high-voltage mode; during working at a low-voltage segment, the mains specification of the distribution network is withina region of 110VAC, and the improved voltage-multiplying valley-filling circuit can work in a high-voltage mode; and an output voltage cannot be reduced to one second of an input voltage, the output voltage is equal to the input voltage and a voltage of a first capacitor in a half-wave period of rectification, so that the valley-filling output voltage is obviously improved. With the improvement ofthe working performance of the valley-filling circuit under a low-voltage state, the valley-filling circuit can be applied within a global voltage range, and the application field of the valley-filling circuit is expanded.