<p>The nonenzymatic synthesis of organics from H₂–CO₂ redox couple forms the foundational basis for prebiotic carbon metabolism. However, constructing comprehensive carbon cycling reaction networks with multiple interlinked subsystems preceding enzymatic catalysis remains challenging. Here, we demonstrate that metallic molybdenum sulfide mimicking Mo-S₂-pterin enzyme drives the construction of hydrothermal CO₂ reaction networks across five carbon sequestration pathways including acetyl-CoA, reductive tricarboxylic acid, 3-hydroxypropionate-4-hydroxybutyrate, dicarboxylate-4-hydroxybutyrate, and ethylmalonyl-CoA pathways. A total of 32 intermediates and end-products are synthesized from CO₂, encompassing five universal metabolic precursors. Spectroscopic and computational studies reveal that molybdenum sulfide containing Mo³⁺ with vacancy-induced distorted octahedral structure promotes the formation of radicals and enhances their adsorption and coupling in aqueous solutions, leading to CO₂ conversion rate of 68.6% and selectivity of up to 70% for C₂₊ carboxylates. The metal sulfide-catalyzed multiple CO₂ reaction networks under extreme conditions could function as a prebiotic precursor to ancient and core metabolic pathways.</p>