In this paper, a novel nanoTiO₂-silk fibroin composite membrane was prepared and characterized by AFM, EDS, FTIR, DSC and XRD, then its mechanical intensity and solubility were investigated. The experiments show, the method of preparation is reasonable; When nanoTiO₂ content is 0.1% (w/w), nanoTiO₂ particles do not reunite and can disperse in the composite membrane with the size of 50 nm; The composite membrane exhibits a sharp 2θ peak at 21.1° in its XRD curve and the decomposition temperature of composite membrane is also 28 K higher than that of pure silk fibroin membrane, which indicates the crystallinity of composite membrane is higher than that of pure silk fibroin membrane; The composite membrane shows better mechanical intensity, but less solubility than pure silk fibroin membrane. Therefore, it can be concluded that nanoTiO₂ particles may induce silk fibroin macromolecule transforming from random coil conformation to β-sheet conformation.