Valve capable of preventing reverse flow

According to the valve capable of preventing backflow, a protruding sealing ring and a supporting seat are connected to the inner wall of an outer fixing sleeve, a valve plate is located between the protruding sealing ring and the supporting seat and connected to the supporting seat through an elastic piece, and the elastic piece is in a compressed state to press the valve plate to the protruding sealing ring; the outer fixing sleeve is connected to the valve inlet or the valve outlet in a flange mode, and the outer fixing sleeve and the inner wall of the valve body are in sealing fit. According to the valve capable of preventing reverse flow, the reverse flow valve assembly is installed on the valve body as a whole in a flange mode, and therefore the installation difficulty of the reverse flow valve assembly is reduced; the reflux valve assembly is independent of the valve body, the machining and maintaining difficulty is lowered, and meanwhile the reliability of the reflux valve assembly is high. 本申请揭示了一种防止