Spherical Bi2WO6 nanoarchitectures with scale of 2–4 μm were prepared by a hydrothermal reaction using bismuth nitrate and ammonium tungstate as raw materials. Ag was deposited on the surface of Bi2WO6via a following facile photoreduction process. The as-prepared samples were characterized by UV-Vis-DRS, BET, XRD, XPS, FE-SEM, and HR-TEM. The results revealed that the monodispersed metallic Ag nanoparticles with average size of 10–15 nm were deposited on the surface of the spherical Bi2WO6 nanoarchitectures. The photocatalytic activities of the samples were evaluated by the photodegradation of RhB and thiophene under visible light irradiation. The results showed that Ag loading greatly improved the photocatalytic activity of Bi2WO6, and the content of loading silver has an impact on the catalytic activity of Bi2WO6. The 0.5at%Ag-loaded Bi2WO6 sample exhibited the best photocatalytic activity in both the decolorization of RhB and desulfurization of thiophene. In addition, the mechanism for the enhancement of the photocatalytic activity of Ag-loaded Bi2WO6 was also investigated by comparison of their PL spectra.