Silver?doped powders with n（Ag⁺）/n（Ti⁴⁺） of 0.001、0.003、0.005、0.010、0.030 and 0.050 and ceramic hollow microspheres loaded with titanium dioxide photocatalyst were prepared by sol?gel method. The prepared catalysts were characterized by SEM, XRD and Uv?Vis DRS, and their photocatalytic properties were tested under xenon lamp light source. The doping mechanism was analyzed using first?principles calculations.The results show that the degradation rate of 0.005Ag?TiO₂ powder after photocatalytic degradation of 10 mg/L methylene blue for 90 min is 76%. It is concluded that n（Ag⁺）/n（Ti⁴⁺）=0.005 is the best doping amount, and the degradation rate of ceramic hollow microsphere supported catalyst for 90 min is 97%. Ag doping can introduce impurity energy levels in the TiO₂ system, so that the valence band electrons can reach the conduction band by hierarchical transition. The calculation results are consistent with the experimental results.