A device for treating regurgitation of a tricuspid valve (4) is disclosed. The device comprises a tricuspid valve plug (21) capable of compressing and expanding and a tricuspid valve plug fixing device used for anchoring the tricuspid valve-in-plug (21) to an orifice of the tricuspid valve (4). The tricuspid valve plug (21) is provided with an inflow end (42, 52) and an opposite outflow end (47, 57), and a prosthetic valve (50, 70) capable of being opened and closed is disposed in the tricuspid valve plug (21). When the tricuspid valve (4) is dosed, the prosthetic valve (50, 70) is automatically closed, and when the tricuspid valve (4) is opened, the prosthetic valve (50, 70) is automatically opened.