We reported a strategy of carbon-negative H2 production in which CO2 capture was coupled with H2 evolution at ambient temperature and pressure. For this purpose, carbonate-type Cux Mgy Fez layered double hydroxide (LDH) was preciously constructed, and then a photocatalysis reaction of interlayer CO32- reduction with glycerol oxidation was performed as driving force to induce the electron storage on LDH layers. With the participation of pre-stored electrons, CO2 was captured to recover interlayer CO32- in presence of H2 O, accompanied with equivalent H2 production. During photocatalysis reaction, Cu0.6 Mg1.4 Fe1 exhibited a decent CO evolution amount of 1.63 mmol g-1 and dihydroxyacetone yield of 3.81 mmol g-1 . In carbon-negative H2 production process, it showed an exciting CO2 capture quantity of 1.61 mmol g-1 and H2 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.