Small-caliber artificial blood vessel with three-layer composite structure, and preparation method of small-caliber artificial blood vessel

The invention provides a small-caliber artificial blood vessel with a three-layer composite structure, and a preparation method of the small-caliber artificial blood vessel. The small-caliber artificial blood vessel comprises a weaving inner layer, an electrostatic spinning intermediate layer and a polyurethane outer layer, wherein the electrostatic spinning intermediate layer is arranged on the outer side of the weaving inner layer; the polyurethane outer layer is arranged on the outer side of the electrostatic spinning intermediate layer; the weaving inner layer comprises a first weaving stand pipe and a second weaving bracket stand pipe; the second weaving stand pipe is a weaving stand pipe with axial yarns, and is arranged on the outer side of the first weaving stand pipe. The small-caliber artificial blood vessel adopts a simulation structure; the weaving stand pipes serve as enhancement layers and are relatively high in compliance; the electrostatic spinning intermediate layer adopts a precise three-dimensional reticular structure, so that coated drugs and growth factors are released step by step in the degradation process, thrombosis is prevented, and cell growth is facilitated; the polyurethane outer layer is relatively high in compliance and adopts a microporous structure, so that biomass transmission is facilitated; both PDO and PLLA are degradable materials, so that gradient degradation can be realized, the contact between the polyurethane material and blood can be reduced, the foreign-body reactions to the PDO and PLLA materials can be prevented, and the long-term patency rate can be improved.