In the context of global carbon capping and carbon neutrality, electrochemical methods for converting CO₂ to CO are among the most promising and valuable methods for harvesting greenhouse gas pollutants and producing renewable energy. On this basis, nickel-doped layered boehmite (Ni–AlO(OH)₃) was grown in situ on reduced graphene oxide (RGO) as a carrier, forming composites with many active sites and good electrical conductivity. The crystal structure, morphology, specific surface area and composition of the samples were characterized. The electrocatalytic carbon dioxide reduction (ECR) performance of these catalysts was evaluated. The results show that the Ni–AlO(OH)₃@RGO catalyst has high product selectivity, with only carbon monoxide and hydrogen as the gas phase products and no liquid phase products, and the carbon monoxide faradaic efficiency (CO FE) can reach 92.20%, while the CO FE of AlO(OH)@RGO and Ni(OH)₂@RGO can reach 44.9% and 88.2%, respectively. It was shown that composite catalysts formed by depositing Ni–AlO(OH)₃ hydroxides on reduced graphene oxide had a higher CO₂RR performance, which was related to the synergistic effect of bimetallic hydroxides and reduced graphene oxide.