The invention relates to a tissue engineering material and a preparation method thereof, in particular to a nano fiber tissue engineering blood vessel and a preparation method thereof. The invention consists of a three-dimensional reticular non-woven film formed by an inner layer of nano fiber and an outer layer of nano fiber; the inner layer of the blood vessel is natural polymer, wherein, calculated by weight, 40 percent to 80 percent is fibroin, 20 percent to 50 percent is gelatine, 0 percent to 20 percent is extracellular matrix protein; while the outer layer of the blood vessel is synthetic polymer. The preparation method is that the natural polymer is dissolved in trifluroroethyl and other solution, while the synthetic polymer is dissolved in hexafluoroisopropanol and other solution, which are respectively prepared into spinning solution; the static electricity spinning technique is adopted to subsequently form the inner and the outer layers on a gather roller; cross-linked treatment is conducted after the inner and the outer layers are taken down, to prepare the nano fiber tissue engineering vessel. The inner layer can simulate the structure of the extracellular matrix, provide good environment for endothelial cells to grow, support adhesion, proliferation and differentiation of the cells, and is good for endothelization of the blood vessel; and the outer layer has goodmechanical performance.