Composite semiconductor photocatalysts with hollow structures can present excellent photocatalytic performance by combining the advantages of composite photocatalyst and hollow structures. However, it is a great challenge to develop a facile synthetic route to realize the composite hollow nanostructures. In the paper, AgCl/TiO2 composite hollow octahedra were synthesized by a facile self-templated method via the direct addition of Ag2O octahedron template into TiCl4 ethanol solution. In the case, AgCl and TiO2 nanoparticles can be simultaneously formed to construct the shell of hollow octahedra along with the alcoholysis and hydrolysis of TiCl4 and the reaction of releasing H+ and Cl- ions with Ag2O template. Obviously, the synthetic method showed some advantages of economic reaction steps and uniform component distribution. After AgCl/TiO2 is illuminated by visible light, partial Ag metal can form in the sample due to the photosensitive property. Further photocatalytic results indicated that the Ag/AgCl/TiO2 hollow octahedron photocatalyst exhibited excellent photocatalytic activity and stability of performance. Importantly, the present Ag2O self-template method was also extended for the synthesis of other hollow octahedra such as AgCl/Bi2O3, AgCl/SnO2 and AgCl. Thus, the present work may provide new insights into design and synthesis of other hollow octahedron photocatalysts.