Anti-deposition check valve

An anti-deposition check valve is disclosed. The anti-deposition check valve comprises: an upper flange having a first opening, and a chamfered ring surface is formed on one side of the first opening; a lower flange having a second opening; a spacer frame disposed between the upper flange and the lower flange; and a sealing element having a tapered plate on the top side of the sealing element, the sealing element being axially movable on the spacer frame, and the annular area of the tapered plate being constantly kept substantially parallel away from or against the chamfered ring surface, wherein the sealing element is moved to an open position or a closed position to correspondingly open or close the first opening of the upper flange, so that the first opening of the upper flange is connected or not to the second opening of the lower flange. Therefore, the problem of poor sealing caused by the accumulation inside the check valve can be avoided.