The invention relates to an I type-endoleak-preventing stent graft system with a spiral villus structure. The I type-endoleak-preventing stent graft system for sealing I type endoleak is characterized by comprising a metal mesh support layer matched with the shape of an artery blood vessel, a covering layer covering the metal mesh support layer and villus layers distributed on the proximal part or on both the proximal part and the telecentric part of the outer side of the covering layer. The villus layers fill the gap formed between an inner wall and the covering layer under the elasticity of the villus layers. Each villus layer is provided with a plurality of villus inside, and each villus is spiral. The I type-endoleak-preventing stent graft system can seal I type endoleak.