Abstract: A connecting union joint with smart connection of an easy-flowing pipe system includes a joint body, wherein an end of the joint body is provided with a pipe connecting device which includes a sliding base, a snapping tooth piece, a reset spring, a spring pad and a snapping ring. The joint body is internally provided with a snap slot. The reset spring is arranged between the spring pad and the sliding base. The sliding base is evenly provided with a plurality of through openings. tooth The snapping tooth of the snapping tooth piece deeply extend into an inner wall of the sliding base and are snapped with an outer peripheral surface of the pipe. An inner wall of the joint body is provided with a moving area for allowing the snapping tooth piece to move therein.