Safety warning device for road and bridge construction and using method

The invention provides a safety warning device for road and bridge construction and a using method, and relates to the technical field of safety warning devices. The safety warning device comprises anupper frame body and a lower frame body, wherein the upper frame body is hinged to the lower frame body, a display screen is installed in the upper frame body through symmetrically-arranged damping locking pieces, and a controller is arranged on the upper frame body under the display screen; alarm lamps are arranged on the upper frame body at the two sides of the controller, and locking mechanisms are arranged in the upper frame body on the outer sides of the alarm lamps; a storage battery is mounted on the lower frame body through the damping locking pieces and a mounting frame; and groovesare symmetrically formed in the lower frame body on the outer side of the storage battery, supporting legs are installed in the grooves through damping locking pieces, and the supporting legs are connected with the lower frame