The invention provides a plug stick for purifying molten steel for continuous casting and a preparation method of the plug stick. The problem that the existing plug stick structure is unreasonable indesign is solved, so that the phenomenon that when the aluminum-containing steel is cast, a tundish water outlet, an integral submersed nozzle bowl part and the inner cavity are blocked are avoided; the plug stick for purifying the molten steel for the continuous casting comprises a stick body and the inner cavity arranged in the center of the stick body, and is characterized in that the stick body is composed of a stick head and a stick body fixed at the bottom of the stick head; the inner cavity penetrates through the stick head and the stick body, and two argon chambers are arranged in thestick body; a ventilating dense net is arranged on the side wall of the stick body close to the stick head, the ventilating dense net communicates with the argon chambers, and two argon nozzles are arranged on the bottom end surface of the stick body; and the two argon nozzles correspondingly communicate with the two argon chambers, not only can the conventional function of the plug stick in the using process be kept, but also the impurity removing function of the plug stick is also endowed.