Disclosed is a valve stent used safely and a valve replacement device having the valve stent, wherein the valve stent includes a tubular supporting net frame and a flared section connected to the end of the supporting net frame, which is connected to all end nodes on a corresponding side of the supporting net frame. The flared sections is located at a precedent release end of the valve stent. An outer rim of the flared section is formed by several curved support bars, and wherein all the end nodes on the supporting net frame corresponding to the positions of the supporting bars are all connected to the supporting bars. Due to the improvements to the structure of existing memory alloy self-expandable valve stents, rhombic vertices existing in isolation which are present in non-end portions of the valve stent are eliminated. While maintaining the mechanical properties of the original structural, this prevents spines from appearing after the valve stent is compressed, and thereby resolving the problem of sheath damage caused by the spines.
