A pre-charging circuit is provided, including a first switch, a second switch, a diode, a first current-limiting apparatus, a capacitor, and an inverter unit. One end of the pre-charging circuit is connected to a power grid. After the first current-limiting apparatus, the first switch, and the diode are connected in series, one end of a line formed by the series connection is connected to one terminal of the capacitor, the other end of the line is connected to a first-phase alternating current of the power grid, and the other terminal of the capacitor is connected to a second-phase alternating current of the power grid via the inverter unit and the second switch successively.