Packaging bag fresh-keeping exhaust valve structure

A packaging bag fresh-keeping exhaust valve structure, being an exhaust valve, comprising a valve body, a valve plate and a preservative;

• the valve body being provided with a partition to partition an internal space of the valve body into a valve chamber and a filling chamber;
• the partition being formed with at least one through hole so that the valve chamber and the filling chamber communicate with each other through the through hole;
• the valve plate being disposed in the valve chamber, an outer peripheral edge of an open end of the valve chamber being provided with a flange extending radially outwardly, a surface of the flange being provided with a first sealing film to confine the valve plate within the valve chamber;
• the preservative being disposed in the filling chamber, an inlet end of the filling chamber being provided with a breathable film to cover the filling chamber and confine the preservative within the filling chamber, and an outer end of the breathable film being provided with a second sealing film to seal the filling chamber;
• wherein the valve plate is completely movable in the valve chamber with no fastening to selectively close or open the through hole, and the valve plate is either planarly attached on the first sealing film to open the through hole or planarly placed on the partition to close the through hole.