Anti-falling sealing washer

The invention discloses an anti-falling sealing washer which is applied to a heat exchange plate of a plate heat exchanger and comprises an upper sealing piece and a lower sealing piece, and the upper sealing piece is pasted to the position, close to the outer side, of the upper end face of the heat exchange plate; the lower sealing piece is adhered to the lower end surface of the heat exchange plate close to the outer side; wherein the upper sealing element and the lower sealing element are symmetrically arranged; mounting grooves are formed in the positions, close to the outer sides, of the upper end faces and the lower end faces of the heat exchange plates. According to the technical scheme, the outwards-protruding inclined face on the upper annular portion of the lower sealing piece is inserted into the inwards-concave inclined face on the upper annular portion of the upper sealing piece, the outwards-protruding inclined face and the inwards-concave inclined face are attached, at the moment, the limiting