Composite silk fibroin/chitosan nanofiber membrane was fabricated by bubbfil electrospinning. The influence of chitosan content on composite membrane's microstructure, mechanical property, and the percentage of water-dissolved were studied experimentally. The result indicated that the crystallinity of electrospun membrane was enhanced by increasing chitosan concentration. It is noteworthy that the percentage of water-dissolved was the minimum when the weight ratio of silkfibroin/chitosan was 70:30. After the composite membrane treated by the methanol, the percentage of water-dissolved of the nanofiber membrane decreased significantly. The strength and elongation at break of composite membrane increased gradually with the increased content of chitosan. Additionally, the electrospun silk fibroin/chitosan membrane showed excellent antibacterial property.