A series of Cu-loaded SrTiO3/TiO2 nanotube heterostructures were synthesized by a facile molten salts method and an impregnation-calcination method. Through adjusting the molar ratio of Sr/Ti, the photocatalytic performance of the samples changed regularly. When Sr/Ti = 0.2, the catalyst showed the highest performance in water splitting and the H-2 generation amount was 0.597 mmol under UV irradiation for 8 h. The enhanced performance of Cu-loaded SrTiO3/TiO2 nanotubes could be attributed to the heterostructures, the small crystallite size, and the reduced band gap inside them.