TiO2 nanotube–nanoparticle mixture was prepared by a rapid anodization process in a perchlorate containing electrolyte followed by an ultrasonic process. Ag–TiO2 nanocomposites were prepared at low temperature in polyethylene glycol (PEG600) solution, in which PEG600 was employed as the stabilizing agent as well as the reducer which can reduce Ag+ on the surface of prepared TiO2 nanocrystals. The synthesized samples were characterized by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray detector, X-ray photoelectron spectroscopy and UV–vis absorption spectroscopy. Results showed that well dispersed Ag nanoparticles with a typical size of 5–10nm can be synthesized on the surface of TiO2 nanocrystals assisted by the PEG600. To investigate the photocatalytic activity of the samples, TiO2 powders with different Ag contents were prepared and employed to decompound methyl orange under UV-light irradiation. Compared with pure TiO2 nanocrystals and commercial P25, a great improvement of photocatalytic performance was found for the Ag–TiO2 nanocomposites. It is believed that the excellent photocatalytic properties of the samples prepared in our experiment mainly result from promoted separation of photogenerated electron-hole pairs and higher reductive power due to the formed heterostructure between TiO2 and Ag as well as the advanced absorption of light due to surface plasmon effect of Ag nanoparticles.