In the present work, degradation of methylene blue (MB) dye in aqueous solution by using hydrodynamic cavitation combined with H2O2 and Bi-doped TiO2 photocatalyst was investigated. Bi-doped TiO2 photocatalyst was prepared by using a sol-gel synthesis method. The synthesized Bi-doped TiO2 material was characterized by X-ray diffraction spectra (XRD), FT-IR and TEM. The effect of various operating parameters such as inlet fluid pressure, solution pH, addition of H2O2 and photocatalyst on the degradation of MB dye were studied. The maximum extent of degradation of methylene blue was obtained at inlet pressure of 5 bar and pH 2. The molar ratio of MB: H2O2 i.e. 1:20 was shown 94.64% of MB decolorization over 60 min. Combination of hydrodynamic cavitation and H2O2 has shown high synergetic effect than the combination of hydrodynamic cavitation and Bi-doped TiO2 photocatalytic process.