Bi0.5Dy0.5VO4 (BDV) oxide solid solution was synthesized by a solid state reaction method and was characterized by XRD, UV-visible DRS, BET, SEM and TEM. It has an appropriate band gap energy of ca. 2.76 eV to absorb visible light, corresponding to an absorption edge of 450 nm. When Pt-Cr2O3 was co-loaded, BDV could split water under UV light and visible light. The amounts of the produced hydrogen and oxygen were about 7.27 and 3.82 mu mol respectively under the irradiation of visible light (lambda > 420 nm) for 2 h. This study indicated that the suitable band gap of BDV for overall water splitting might be attributed to the formation of new VB due to Bi6s participating in the electronic structure.