A locking device (200, 200a), comprising: a first flange, the first flange being adapted to be fixed on a first shaft; a second flange, the second flange being adapted to be fixed on a second shaft; a synchronizing ring, the synchronizing ring being normally connected to the first flange to be adapted to rotate synchronously with the first flange, and the synchronizing ring being slidable relative to the first flange; and a driving component, the driving component selectively pushing the synchronizing ring to slide from an unlocked position to a locked position in an axial direction of the first flange, wherein when the synchronizing ring is in the locked position, the synchronizing ring is connected to the second flange to be adapted to rotate the second flange synchronously with the first flange, and when the synchronizing ring is in the unlocked position, the synchronizing ring is separated from the second flange, characterized in that the driving component comprises: an electromagnet, the electromagnet being adapted to be fixed on a housing; an ejector pin, one end of the ejector pin being slidably connected to the first flange; and a driving member, the driving member being provided with a driving profile, and the other end of the ejector pin being matched with the driving profile, wherein the electromagnet is selectively energized, and when the electromagnet is energized, the driving member is fixed to drive the ejector pin to move in the axial direction of the first flange through the driving profile, and to push the synchronizing ring to slide from the unlocked position to the locked position, preferably wherein the ejector pin and the driving profile are both multiple and in one-to-one correspondence, and the ejector pins are spaced apart in a circumferential direction of the first flange. a first flange, the first flange being adapted to be fixed on a first shaft; a second flange, the second flange being adapted to be fixed on a second shaft; a synchronizing ring, the synchronizing ring being normally connected to the first flange to be adapted to rotate synchronously with the first flange, and the synchronizing ring being slidable relative to the first flange; and a driving component, the driving component selectively pushing the synchronizing ring to slide from an unlocked position to a locked position in an axial direction of the first flange, wherein when the synchronizing ring is in the locked position, the synchronizing ring is connected to the second flange to be adapted to rotate the second flange synchronously with the first flange, and when the synchronizing ring is in the unlocked position, the synchronizing ring is separated from the second flange, characterized in that the driving component comprises: an electromagnet, the electromagnet being adapted to be fixed on a housing; an ejector pin, one end of the ejector pin being slidably connected to the first flange; and a driving member, the driving member being provided with a driving profile, and the other end of the ejector pin being matched with the driving profile, wherein the electromagnet is selectively energized, and when the electromagnet is energized, the driving member is fixed to drive the ejector pin to move in the axial direction of the first flange through the driving profile, and to push the synchronizing ring to slide from the unlocked position to the locked position, preferably wherein the ejector pin and the driving profile are both multiple and in one-to-one correspondence, and the ejector pins are spaced apart in a circumferential direction of the first flange. an electromagnet, the electromagnet being adapted to be fixed on a housing; an ejector pin, one end of the ejector pin being slidably connected to the first flange; and a driving member, the driving member being provided with a driving profile, and the other end of the ejector pin being matched with the driving profile, wherein the electromagnet is selectively energized, and when the electromagnet is energized, the driving member is fixed to drive the ejector pin to move in the axial direction of the first flange through the driving profile, and to push the synchronizing ring to slide from the unlocked position to the locked position, preferably wherein the ejector pin and the driving profile are both multiple and in one-to-one correspondence, and the ejector pins are spaced apart in a circumferential direction of the first flange.