A recoverable, safe and reliable valve stent for unidirectional flow of human lumen which can be implanted temporarily or for a long term and is used in the interventional therapy so as to obstruct from anisotropic flow, in the case of lung diseases. It comprises a cylindrical stent made up of memory alloy material. In particular, an elastic diaphragm is arranged inside the cylindrical stent and at least one gap is arranged on the diaphragm so that the spring piece is divided into a bendable section. One end of the cylindrical stent is provided with a fixed rear clip which is used to fix the alloy material making up the cylindrical stent. The rear clip is provided with screwthreads which can be connected with the conveyor. The stent in the present invention is in a structure without hook body, so the stent can be accurately positioned, adjusted and placed or recovered in double directions with strong anti-backflow ability.