A four-way plug valve is a plug valve with four ports. By rotating the plug with specific through-holes, it enables multi-path switching, flow diversion, or merging of fluids (such as two inlets and two outlets, one inlet and three outlets, etc.), and can replace multiple single-path or three-way valve combinations. Its compact structure significantly reduces pipeline connection points and leakage risks, while retaining the advantages of rapid opening and closing and low flow resistance of plug valves. It is suitable for industrial scenarios requiring complex fluid path control and limited space. It is widely used in petrochemical, fine chemical, pharmaceutical, and water treatment fields, for applications such as multi-media mixing, pipeline reversing, and multi-station fluid distribution.