A power supply circuit, comprising a power factor correction circuit and a direct current power supply for supplying a direct current voltage, the power factor correction circuit comprising: a main correction circuit and a switch module, wherein: the main correction circuit comprises: a first correction circuit and a second correction circuit that are configured to perform power factor correction on an forward alternating current voltage, and a third correction circuit and a fourth correction circuit that are configured to perform power factor correction on an inverse alternating current voltage, wherein output terminals of the first correction circuit, the second correction circuit, the third correction circuit, and the fourth correction circuit are electrically connected; the switch module comprises first switch units that are connected in parallel between an input terminal of the first correction circuit and an input terminal of the fourth correction circuit, and second switch units that are connected in parallel between an input terminal of the second correction circuit and an input terminal of the third correction circuit; the first switch units and the second switch units each comprise two controlled switches that are connected in series, wherein a voltage input terminal connected to a voltage input terminal providing an alternating current input voltage is set between the two controlled switches; the switch module in the power factor correction circuit is connected to an alternating current power supply, and the alternating current power supply is configured to provide an alternating current input voltage; a direct current power supply for supplying a direct current voltage, the direct current power supply is mounted in the power supply circuit by using a switch component, and is configured to provide a direct current voltage when the alternating current power supply fails; and the direct current power supply is mounted between an neutral wire and at least two of three phases of output terminals of the alternating current power supply each by using the switch component. the main correction circuit comprises: a first correction circuit and a second correction circuit that are configured to perform power factor correction on an forward alternating current voltage, and a third correction circuit and a fourth correction circuit that are configured to perform power factor correction on an inverse alternating current voltage, wherein output terminals of the first correction circuit, the second correction circuit, the third correction circuit, and the fourth correction circuit are electrically connected; the switch module comprises first switch units that are connected in parallel between an input terminal of the first correction circuit and an input terminal of the fourth correction circuit, and second switch units that are connected in parallel between an input terminal of the second correction circuit and an input terminal of the third correction circuit; the first switch units and the second switch units each comprise two controlled switches that are connected in series, wherein a voltage input terminal connected to a voltage input terminal providing an alternating current input voltage is set between the two controlled switches; the switch module in the power factor correction circuit is connected to an alternating current power supply, and the alternating current power supply is configured to provide an alternating current input voltage; a direct current power supply for supplying a direct current voltage, the direct current power supply is mounted in the power supply circuit by using a switch component, and is configured to provide a direct current voltage when the alternating current power supply fails; and the direct current power supply is mounted between an neutral wire and at least two of three phases of output terminals of the alternating current power supply each by using the switch component.