Semiconductor photocatalytic technology as an effective and environmental-friendly method for the treatment of Cr(Ⅵ)-containing wastewater[1,2].g-C3N4/SnS2 nanocomposites were synthesized at 150 ℃ for 12 h by using in suit hydrothermal method with different sources and dosage of g-C3N4 and photocatalytic activity of g-C3N4/SnS2 nanocomposites obtained by photocatalytic reduction treatment aqueous Cr(Ⅵ) were investigated.It was revealed that the photocatalytic reduction activity of g-C3N4//SnS2 nanocomposite depended on their compositions and synthesis method,and g-C3N4/SnS2-C possessed the highest photocatlytic activity with urea as the reaction raw material.And also the photocatalytic activity of g-C3N4/SnS2 nanocomposite depended on their composition and g-C3N4/SnS2-C with a suitable content (40 mass%) of g-C3N4 possessed the highest photocatalytic activity.