Abstract: Ag doped TiO₂ was synthesized by Sol-Gel method. The composite was characterized by X-ray Diffraction(XRD), Scanning Electron Microscope(SEM), Fourier Transform Infrared Spectoscopy(FT-IR), Thermogravimetric and Differential Scanning Calorimetric, and UV-Vis Diffuse Reflectance Spectroscope(DRS). Used methyl orange as the model pollutant and studied its photocatalytic activity by using different calcination temperature and silver doped amount. It revealed that Ag doped TiO₂ had improved the photocatalytic activity of TiO₂ under UV light and visible light. When the Ag doping amount was 1.00 %, calcination temperature was 450 ℃, the amount of catalyst was 0.05 g. Under visible light, the degradation rate reached 92.57 % when the Ag doped TiO₂ degradation after 4 h, is 4.51 times higher than TiO₂. Under UV light, the degradation rate reached 84.54 % when degradation after 2 h, is 2.27 times higher than TiO₂.