A guardrail locking device, which is used to install a safety guardrail on a railway track comprising: - a card plate, - a press plate, - a bottom plate arranged horizontally, - a connecting rod, attached to the press plate, - a number of fasteners (40, 50, 60), - an adjusting part is arranged on the bottom plate to adjust the distance between the card plate and the press plate, wherein: - the card plate and press plate spacing can be arranged on the bottom plate, - the card plate and the press plate are arranged in a vertical parallel arrangement or a tilted extension arrangement, - one of the card plate and press plate is connected to the bottom plate in one piece, the other one of the card plate and the press plate is detachable and mountable on the adjusting part of the bottom plate, - the card plate and the press plate can be locked on two opposite sides of a rail of the railway track respectively through the fasteners (40, 50, 60), characterized in that: - the bottom of the bottom plate is provided with a card slot (43, 54c), and the middle of the slot bottom is provided with a bayonet (44, 55c), the bayonet runs vertically through the bottom plate, the bayonet (44, 55c) is arranged in a horizontal direction as long as the card slot (43, 54c), and the bottom of the card slot on both sides of the bayonet (44, 55c) forms a two-limit step surface, and - the bottom of the card plate surface or the bottom of the press plate surface, when detachable and mountable on the adjusting part of the bottom plate, is provided with a buckle part arrangeable through the bayonet (44, 55c), the buckle part is an inverted t-shape setting, which includes a connecting column and a limit table at the bottom end of the connecting column, the connecting column is arranged in the bayonet (44, 55c) of the bottom plate, and the limit table card is arrangeable on the bottom surface of the groove. - a card plate, - a press plate, - a bottom plate arranged horizontally, - a connecting rod, attached to the press plate, - a number of fasteners (40, 50, 60), - an adjusting part is arranged on the bottom plate to adjust the distance between the card plate and the press plate, wherein: - the card plate and press plate spacing can be arranged on the bottom plate, - the card plate and the press plate are arranged in a vertical parallel arrangement or a tilted extension arrangement, - one of the card plate and press plate is connected to the bottom plate in one piece, the other one of the card plate and the press plate is detachable and mountable on the adjusting part of the bottom plate, - the card plate and the press plate can be locked on two opposite sides of a rail of the railway track respectively through the fasteners (40, 50, 60), - the bottom of the bottom plate is provided with a card slot (43, 54c), and the middle of the slot bottom is provided with a bayonet (44, 55c), the bayonet runs vertically through the bottom plate, the bayonet (44, 55c) is arranged in a horizontal direction as long as the card slot (43, 54c), and the bottom of the card slot on both sides of the bayonet (44, 55c) forms a two-limit step surface, and - the bottom of the card plate surface or the bottom of the press plate surface, when detachable and mountable on the adjusting part of the bottom plate, is provided with a buckle part arrangeable through the bayonet (44, 55c), the buckle part is an inverted t-shape setting, which includes a connecting column and a limit table at the bottom end of the connecting column, the connecting column is arranged in the bayonet (44, 55c) of the bottom plate, and the limit table card is arrangeable on the bottom surface of the groove.