As an efficient hydrogen precipitation site, MoSx shows great promise for energy production and environmental remediation applications due to its low cost, easy modulation, multiple complex valence states, and excellent catalytic performance. Therefore, the development of MoSx synthesis strategies, catalytic enhancement mechanisms, and catalytic applications is reviewed. First, six synthesis strategies regarding MoSx are mainly outlined: electrochemical deposition, photodeposition, hydrothermal/solvent thermal, pulsed laser deposition, precipitation, and calcination, and their advantages and disadvantages are described in detail. Second, catalytic enhancement mechanisms of the composite strategies are elucidated based on the trends of MoSx electronic properties, valence species, light‐absorption range, and interfacial charge transfer. Third, applications of MoSx in photo(electro)catalysis in recent years are systematically reviewed. Finally, the current shortcomings and future research directions of MoSx are discussed from the perspectives of synthesis strategies and practical applications, respectively.