Constructing heterojunction semiconductor materials with a strong interfacial interaction are emerging as a forefront strategy for promoting excellent photocatalytic performance. Herein, we report a novel SnS2/SnO2 heterojunction material via in-situ trace vulcanization strategy to coat SnS2 on the SnO2. The thickness of the coating layer can be regulated by controlling the content of SnS2. Moreover, molar ratio of S to Sn, particle size of SnO2 precursor, and vulcanization time that governs the SnS2 content of heterojunction catalyst were controlled to optimize photocatalytic performance. SnS2/SnO2 heterojunction catalyst with 19.5% SnS2 content delivered a ultrahigh visible-light activity in Cr(VI) degradation, remarkably superior to the inert SnO2 precursors and full-vulcanized SnS2 under identical testing conditions. The enhanced interfacial interaction can remarkably enhance the separation and transfer of photogenerated charges. The systematic methodology of interface regulation in SnS2/SnO2 system reported in this work would promote the understanding of nano-heterojunction material for high-performance water treatment application.