The present invention provides a valve stent used safely comprising a supporting net frame, and a flared section connected to an end of the supporting net frame wherein the flared section is connected to all end nodes located at a corresponding side of the supporting net frame, the flared section is grid shaped, and a number of intersection points of the grids decreases along an axial direction away from the supporting net frame. The present invention also provides a valve replacement device comprising an above valve stent and a prosthesis valve fixed inside the supporting net frame.
