Ternary TiO₂–SiO₂–Ag nanocomposites with enhanced visible-light photocatalytic activity have been synthesized through a facile biomimetic approach by utilizing lysozyme as both inducing agent of TiO₂ and reducing agent of Ag⁺. TiO₂ nanoparticles (∼280 nm) are at first fabricated by the inducing of lysozyme. Afterward, SiO₂ layers are formed as “pancakes” stuck out of TiO₂ nanoparticles through a sol–gel process. Finally, Ag nanocrystals (∼24.5 nm) are deposited onto the surface of TiO₂–SiO₂ composites via the reduction of lysozyme, forming TiO₂–SiO₂–Ag nanocomposites. The resultant nanocomposites display a high photocatalytic activity for the degradation of Rhodamine B under the visible-light irradiation, which can be attributed to the synergistic effect of enhanced photon absorption from the surface plasma resonance of Ag nanocrystals and the elevated adsorption capacity for Rhodamine B from the high specific surface area of SiO₂. This study may provide some inspiration for the rational design and the facile synthesis of composite catalysts with a high and tunable catalytic property through a green, efficient pathway.