Abstract: The Bi₄Ti₃O₁₂was prepared by hydrothermal method using bismuth nitrate as the bismuth source and tetrabutyl titanate as the titanium source, and then the Bi₄Ti₃O₁₂ was reduced by light to obtain Ag@AgCl/Bi₄Ti₃O₁₂ nanocomposites using silver nitrate as the silver source and hydrochloric acid as the chlorine source. The compo-sition and structure of the as-prepared nanocomposites were characterized by XRD, UV-Vis DRS, SEM, TEM, BET and XPS, etc. Taking the decolorization rate of methyl orange (MO) as an evaluation standard, the visible light catalytic performance and active substances of the as-prepared catalyst were investigated. The results show that the prepared Bi₄Ti₃O₁₂ has a stacked curd-shaped nanosheets structure and Ag@AgCl particles deposite between the sheets, the specific surface area of Ag@AgCl/Bi₄Ti₃O₁₂ increases to 14.30 m²/g, and the absorption of visible light is enhanced. The decolorization rate can attain 96.71% when the 80 mL 10 mg/L MO solutions were irradiated under the 300 W xenon lamp for 30 min using 0.5 g/L Ag@AgCl/Bi₄Ti₃O₁₂, which is 38.28% higher than that of pure Bi₄Ti₃O₁₂. The degradation experiment has strong cycle stability and superoxide radicals (•O₂⁻) plays a decisive role in the degradation process.