In this paper, the orthorhombic nano-spherical tin dioxide and orthorhombic bismuth tungstate which are aggregated from flake to spherical structure were prepared by hydrothermal method, and then they were compounded to prepare the composite photocatalytic material of tin dioxide/bismuth tungstate. X-ray diffraction (XRD), scanning electron microscope (SEM), specific surface area tester (BET) and UV-Vis spectrophotometer were used to characterize the structure, morphology, specific surface area, pore volume and aperture and optical properties of the composite samples. The photocatalytic activity of tin dioxide/bismuth tungstate composites was studied by iodine tungsten lamp to simulate sunlight and using tin dioxide, bismuth tungstate and tin dioxide/bismuth tungstate composites as catalysts to degrade rhodamine B(RhB). The degradation rates of rhodamine B by tin dioxide, bismuth tungstate and tin dioxide/bismuth tungstate are 9%, 22% and 30%, respectively. Experiments show that the photocatalytic activity of tin dioxide/bismuth tungstate composite is higher than that of single tin dioxide and bismuth tungstate under visible light.