Rapid compounding of semiconductor carriers is a crucial element limiting the performance of semiconductor photocatalytic decomposition of aqueous hydrogen, and the rational design of heterojunction is one effective method to improve the performance. In this paper, W18O49/Mn0.45Cd0.55S composite materials were prepared by basic hydrothermal and solvent-thermal strategy, additionally, S-scheme heterojunction was constructed between W18O49 and Mn0.45Cd0.55S by the analysis of the energy band structure. Furthermore, the W18O49/Mn0.45Cd0.55S-10 has excellent achievement and stability, and the photocatalytic production of hydrogen under visible light can reach up to 32.47 mmol g−1 h−1, which is 2.9 folds higher than Mn0.45Cd0.55S. The apparent quantum efficiencies (AQE) of Mn0.45Cd0.55S and W18O49/Mn0.45Cd0.55S-10 were 9.2 % and 16.5 %, respectively. The S-scheme heterojunction effectively ameliorates the space charge separation for W18O49 and Mn0.45Cd0.55S. This work may prove to be instructive for synthesizing remarkable performing S-scheme heterojunction photocatalysts.