A stent delivery system is described. The system includes an outer sleeve assembly with an outer sleeve body, an outer sleeve handle fixed to one end of the outer sleeve body, and an outer sleeve tip connected to an opposing end of the outer sleeve body. The system also includes an inner sleeve assembly, which has a push tube sleeved in the outer sleeve body, an inner sleeve handle fixed to the rear end of the push tube, a stent placing tube connected to the front end of the push tube, and an inner sleeve tip set at the front end of the stent placing tube. The system also includes a snap ring fixed on an outer wall of the push tube and provided between the outer sleeve handle and the inner sleeve handle. The outer sleeve tip includes a stepped surface.