Abstract: A flush valve includes a dual flush body for connecting to a flapper overflow tube of a bath-sanitation product, a dual control switch box and a positioning base, wherein an elastic sealing gasket is provided on the positioning base and matching with a sealing layer of a flapper base, the dual control switch box comprises a control chain component, a control rotating shaft is mounted inside a rotating shaft cavity of the dual control switch box, wherein one end of the control rotating shaft is connected to a handle, the other end of the control rotating shaft is connected to a push-button by a control swing rod, and the control rotating shaft is connected to the control chain component.