Abstract: A one-way valve having vacuum breaking and flow-guiding functions is disclosed. It mainly includes a water supplier, a circular wing, and a one-way valve. The water supplier has at least one first inlet, an outlet and a vacuum valve. The outlet is disposed on said water supplier and extending to an interior of a vacuum valve. The vacuum valve connects with a water guiding element. The vacuum valve has a receiving space and a vacuum hole communicating with the receiving space. This circular wing has a channel, a circular flange and a pivoting element. The circular wing is disposed in the receiving space. The circular flange is mounted on the circular wing and extending outward and disposed in the receiving space. A gap is disposed between one end of the circular flange and an inner wall of the receiving space; and a pivoting portion for pivoting with said one-way valve. This one-way valve is rotatable so as to open or close said channel approximately within 90 degrees.