A single semiconductor remains a great challenge for photocatalysis due to highly recombination of charge carriers. However, construction of multiple heterojunctions photocatalysts is an effective way for photocatalysis technique. Herein, two-dimensional sheet-like highly oriented SnS2/RGO/Ag (SRA) nanocomposites with multiple junctions including schottky- and RGO-n junctions designed and synthesized via hydrothermal strategy followed by in situ sequential UV reductions. The as-prepared SRA nanocomposites exhibited superior photo electrochemical conversion efficiencies and photocatalytic activities for the degradation of typical antibiotics Norfloxacin (NOR) under simulated solar light condition, with the highest removal ratio of 94%. XPS and low temperature EPR technology demonstrates the existence of oxygen vacancies and chemical bond effect among SnS2, Ag and RGO components. Highly oriented crystal facet and efficient spatial charge carrier separations and interfacial transfers in the photo-induced redox reactions are evidenced by various physical techniques. Interestingly, in this paper, RGO was proposed to act as holes trapper to improve photo responsive charge separation in great extent. The mechanism of photoinduced redox reactions including the pathways of interfacial charges transfers and ROS species generations have been proposed in terms of the Density Functional Theory (DFT) quantum calculations and the outcomes of various physicochemical characterizations over SRA nanocomposites.