Abstract We reported a strategy of carbon‐negative H 2 production in which CO 2 capture was coupled with H 2 evolution at ambient temperature and pressure. For this purpose, carbonate‐type Cu x Mg y Fe z layered double hydroxide (LDH) was preciously constructed, and then a photocatalysis reaction of interlayer CO 3 2− reduction with glycerol oxidation was performed as driving force to induce the electron storage on LDH layers. With the participation of pre‐stored electrons, CO 2 was captured to recover interlayer CO 3 2− in presence of H 2 O, accompanied with equivalent H 2 production. During photocatalysis reaction, Cu 0.6 Mg 1.4 Fe 1 exhibited a decent CO evolution amount of 1.63 mmol g −1 and dihydroxyacetone yield of 3.81 mmol g −1 . In carbon‐negative H 2 production process, it showed an exciting CO 2 capture quantity of 1.61 mmol g −1 and H 2 yield of 1.44 mmol g −1 . Besides, this system possessed stable operation capability under simulated flu gas condition with negligible performance loss, exhibiting application prospect.