Because of the development of nanotechnology in recent years， various novel functional nanomaterials have been used in the remediation of water pollution. As the most studied two-dimensional transition metal dichalcogenide nanomaterial， molybdenum disulfide （MoS₂） has unique structures and excellent physicochemical properties， leading to promising environmental capabilities in the field of water-environment remediation. MoS₂ and MoS₂-based nanocomposites are characterized by a large specific surface area， multiple active sites and strong photocatalytic activity， which can effectively remove heavy metal ions （e.g.， Co²⁺， Cd²⁺， Cu²⁺， Pb²⁺， Hg⁺， and Cr³⁺） and organic pollutants （e.g.， oils， organic dyes， and antibiotics） in a water environment through adsorption， redox and photocatalytic degradation. They have become a hot topic in water pollution remediation research. In this review， the effects of morphology， surface modification， phase， and surface defects of MoS₂ on the removal performance of water pollutants are described. In addition， various synthesis methods and structural characteristics of MoS₂ and MoS₂-based binary and ternary nanocomposites are summarized. The adsorption， catalytic， and redox mechanisms of MoS₂ and MoS₂-based nanocomposites for the removal of heavy metals and organic pollutants， as well as the main influencing factors and mechanisms， are discussed. In addition， the environmental risk assessment of MoS₂ and its oxidation products and the methods for recycling MoS₂ and its nanocomposites are reviewed. Finally， the research direction and application potential of MoS₂ and MoS₂-based nanocomposites are discussed， which lays a theoretical foundation for the further study of MoS₂ in water-environment remediation. Further research should focus on a more facile and low-cost method for the synthesis of MoS₂ nanocomposites with good stability， high-efficiency performance and good environmental sustainability. Meanwhile， the long-term environmental transformations， as well as the impact of MoS₂ and MoS₂-based nanocomposites on the ecological system and human health， must be thoroughly investigated before large-scale industrial applications in water-environment remediation.