Wastewater management has become necessary in this industrialized era to meet the water needs of the world. Wastewater is one of the major crises in depletion of the environment. Photocatalysis is considered as the best way to remove pollutants. Therefore, in this study, pure and g-C3N4-SnWO4 nanocomposites were produced employing hydrothermal route. Prepared composites were studied by various techniques. SnWO4 band gap were altered by introduction of g-C3N4. The morphology was uniformly developed by the addition of g-C3N4 to the SnWO4. Evans Blue dye was employed as model pollutant. The photocatalytic action was improved by adding g-C3N4, which formed a heterojunction with SnWO4. The calculated rate constant was 0.000878, 0.0068, 0.01 and 0.0122 min-1 for EB, SnWO4-EB, 0.1 g g-C3N4-SnWO4-EB and 0.2 g g-C3N4-SnWO4-EB. The rate constant increased for 0.2 g g-C3N4-SnWO4 photocatalyst. A heterojunction appeared between g-C3N4 and SnWO4 facilitated SnWO4 for better e-/h+pair's separation and a lower recombination rate, which increased photocatalytic action of product. 0.2 g of g-C3N4-SnWO4 is a promising candidate for future wastewater degradation.