Stent implantation for intracranial stenosis is a very effective method for treating intracranial stenosis. Stent implantation is a minimally invasive procedure done intravascularly through femoral artery vascular puncture, and there are two types of stents applied in the procedure: 1) balloon-expanded stents: after placing the balloon at the stenosis site, injecting a contrast agent to expand the balloon and release the stent into the stenosis site; 2) self-expanding stents: the stent must be placed at the stenosis site, first expanded with a balloon, and then released.