Surface modification of plasma treatment was employed to improve the interface between silk fibroin (SF) powder and polyurethane (PU) in preparation of SF powder/PU blend film. Morphology analysis showed that plasma-treated blend film became dense and compact. The water vapor permeability of blend film from treated powder was significantly lowered. Plasma-treated artificial blood vessel was nearly waterproof, of which the water permeability was about 1/40 of the original value. Correspondingly, the compliance of plasma-treated vessel was enhanced remarkably, indicating it has better elasticity and flexibility which is more suitable for its application in tissue engineering.