The invention discloses a vein self-expanding stent which comprises a middle netted supporting portion and two-end supporting portions, wherein the two-end supporting portions are arranged at two endsconnected with the middle netted supporting portion. The middle netted supporting portion comprises at least two S-shaped or inverted S-shaped wavy annular arrangement structures which are sequentially connected along the circumferential direction or the circumferential direction with a certain inclined angle, adjacent annular arrangement structures are connected through at least one connecting rod, the two-end supporting portions comprise front end bodies and at least one connecting structure, the connecting structures are used for connecting the front end bodies with the middle netted supporting portion, the front end bodies are net rings, and diamond-shaped basic units are sequentially connected to form the net rings. The stent has high fracture resistance, is good in flexibility, radial supporting capacity and anchoring capacity and high in self-expansion capacity and can axially and adaptively expand and contract, and expansion of a vein is facilitated.