Co-doped (Fe3+-N,S) TiO2/SiO2-multiwalled carbon nanotubes (MWCNTs) photocatalyst thin films have been prepared via the peroxo titanic acid (PTA) solution as the TiO2 source via sol-gel method. The samples were analyzed by Fourier-transform infrared spectroscopy and UV-Vis spectroscopy. The photocurrents of prepared photocatalysts were measured using an automated potentiostat. The photoactivities of photocatalyst thin films with various MWCNT content were tested in the degradation of methylene blue (MB) under UV and visible light irradiation. The optimal concentration of MWCNTs was 0.05 wt%. The results showed that the co-doped samples with MWCNTs exhibited higher photocatalytic activity than no-doped TiO2/SiO2. The outstanding photocatalytic activity could be attributed to the synergistic effect of co-dopants and MWCNTs which may act as a narrowing energy band gap state in the TiO2 lattice and reducing the recombination rate of electron/hole, resulting in enhancing the photocatalytic activity of co-doped TiO2/SiO2-MWCNTs.