The invention discloses an intravascular stent in type of a supporting rib having mortise and tenon joint structure and relates to the medical treatment field of intravascular intervention. A helical support rib, with one end having a tenon and one end having a mortise, is connected with an S-shaped connecting rib. A wedged boss is designed at the tenon, a through hole is formed at the mortise, and a slide slot is formed between the tenon and the mortise. In a gripped state, the support rib is helical, and the wedged boss is fastened in the slide slot; in an expanding state, the wedged boss slides along the slide slot, the tenon enters the through hole of the mortise at the time the wedged boss slides to the tail ends of the slide slot, and the tenon continues to move circumferentially to squeeze the through hole under action of radial expanding pressure, and then enters the mortise finally to be jointed with the same completely. The tenon and the mortise of the support rib are jointed completely, the wedged boss is inserted to the through hole completely, and the support rib expands until being changed into a closed circular ring structure. Matching between the tenon and mortise joint structure and matching between the wedged boss and the through hole prevent the stent from radial expanding or contracting; thus, supporting performance of the stent is improved.