Stable and efficient hydrogen production has always been the focus of industry, and steam reforming of ethanol (SRE) is one of the most robust, renewable and cheap technologies. To develop excellent SRE catalysts highly resisting coke formation and metal sintering, La, Tb, and Zr have been doped as a third metal into Ni-CeO₂ catalyst using a sol-gel method. The size and dispersion of Ni nanoparticles, surface oxygen vacancies and metal-supported interaction have been finely tuned, with which the catalytic performance is closely associated. La-doped ceria supported Ni (Ni-CeLa_0.20) exhibited superior catalytic performance, which is ascribed to its large Ni active surface area, abundant oxygen vacancies and suitable metal-supported interaction. DFT calculations showed that the doping of La into Ni-CeO₂ can promote the generation of oxygen vacancies and facilitate the dissociation of water. On Ni-CeLa_0.20, complete conversion of ethanol and stable hydrogen production have been maintained in the 3000-min test. The coke deposition is only 0.48 mg_c/g_cat h at 600 °C under the GHSV of 55920 mL/g_cat∙h.