The invention relates to a BiVO4 nano photoelectrode and application thereof in the aspect of hydrogen production from water splitting, which can increase photocurrent and greatly improve the efficiency of quantum conversion. The BiVO4 nano photoelectrode comprises a BiVO4 nano-pore thin film, and BiVO4 is doped with metal cation, wherein the metal cation is one or a mixture with an arbitrary proportion of more than two of Sr<2+>, Ba<2+>, Cr<6+> and W<6+> by arbitrary proportion. As an improvement of the invention, the surface of the BiVO4 nano-pore thin film is also modified with a catalyst, wherein the catalyst is one or a mixture with an arbitrary proportion of more than two of the oxides of the hydroxides of Rh, W, Mo, Co, Fe, Mn and Ni. Compared with a pure BiVO4 electrode, the quantum conversion efficiency of the invention is greatly increased and reaches 70 percent within a wavelength range of 360-450nm, and a photoresponse range is broadened to 510nm.