In this work, we reported a facile preparation of mesoporous silica materials assisted by a commercial polystyrene-block-polybutadiene-block-polystyrene (PS-b-PB-b-PS) triblock copolymer. For this purpose, the PS-b-PB-b-PS triblock copolymer was first functionalized with (3-mercaptopropyl)triethoxysilane via a thiol-ene radical addition approach, and then the functionalized triblock copolymer with the midblock bearing triethoxysilane moieties was employed to perform intercomponent sol-gel reactions with tetraethoxysilane (TEOS) to obtain the organic-inorganic gels. The organic-inorganic gels with variable compositions were then used as precursors to obtain mesoporous silica via pyrolysis at elevated temperatures. The functionalized triblock copolymer was characterized by means of Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and small-angle X-ray scattering (SAXS). The results of SAXS, transmission electron microscopy, and Brunauer-Emmett-Teller measurements indicate that the mesoporous silica materials were successfully obtained and the porosity of the materials can be modulated with the mass ratios of the functionalized triblock copolymer to the precursor of silica (viz. TEOS).