Abstract: Under the dual impetus of global climate governance and carbon neutrality strategies, photothermal catalytic CO2 hydrogenation has emerged as a research hotspot due to its potential for carbon emission reduction and value in synthesizing high-value-added chemicals. A series of MoS2 catalysts with three-dimensional flower-like microspheres self-assembled from ultrathin nanosheets are synthesized via hydrothermal method by controlling the mass ratio of sulfur to molybdenum precursors. Results demonstrate that the selectivity of the optimized MoS2-1.5 catalyst for C2H6 reaches 69.2% and the yield is 253.66 μmol/(gcat·h) under 1.2 W/cm2 light. At the same time, our research results confirm that CO2 conversion efficiency and ethane selectivity can be effectively improved by adjusting the light intensity and extending the light time; and the significant advantages of higher CO2 conversion efficiency and product selectivity under photothermal catalysis conditions are highlighted by comparing with themocatalysis. Moreover, the excellent stability of MoS2 showcases the unique advantages of two-dimensional sulfides in carbon chain growth reactions, providing new insights for designing photothermal catalysts to convert carbon dioxide into high value-added chemicals under mild conditions.