This work reports a strategy to promote the low-temperature CO₂ methanation on the Ni-based catalyst by tuning the surface oxygen vacancy and medium-strength basic sites of the CeO₂ support and thus changing the reaction pathway. La species was introduced into CeO₂ support and calcined at 600 °C (CeO₂-La-600) to form a La-Ce-O solid solution with a thin La₂O₂CO₃ layer on the surface, generating more basic sites and oxygen vacancies. This unique structure facilitated the adsorption and direct dissociation of CO₂. Over Ni/CeO₂-La-600, the reaction follows the HCOO* and *CO pathways, while over Ni/CeO₂-600, the reaction occurs via the HCOO* pathway only. The decomposition of CO₂ * to *CO is energetically more favorable than hydrogenation to HCOO* on Ni/CeO₂-La-600, resulting in its higher catalytic performance at low temperatures. This work unravels the complex interplay among oxygen vacancy, basic site, and reaction pathway in CO₂ methanation over the Ni-based catalysts.