In order to prepare the Ni-based heterogeneous catalyst with high activity, easy separation and low cost, Ni-CeO2/SiO2 catalyst was prepared by reverse microemulsion method with nickel nitrate and cerium nitrate as raw materials and nano-SiO2 as support. The microstructure, composition, particle size distribution and electronic structure of the catalyst were characterized by SEM, TEM, XRD, and XPS. Ni-CeO2/SiO2 catalyst was used to catalyze the hydrogenation of carbon dioxide to formic acid, and the influence of reaction condition on formic acid yield was investigated. The results show that Ni-CeO2/SiO2 is spherical, the morphology is regular, the average particle size is 60.7 nm, and the active component Ni-CeO2 is 1.5 nm, which belongs to nanoclusters. The Ni and Ce loading of Ni-CeO2/SiO2 are 2.5% and 2.1%, respectively. The specific surface area is 453 m2/g. The formic acid yield reached 77.8% with 0.1 mol/L aqueous solution of KHCO3 as CO2 source at 200 ℃ and 3 MPa in 2 h. The introduction of CeO2 can not only promote the dispersion of Ni, but also induce the electron transfer from Ni to CeO2 due to the difference of work function between Ni and CeO2, forming a Niδ+-(CeO2)δ? hetero junction which can induce the H2 heterocleavage, thereby improving the catalytic activity of Ni-CeO2/SiO2.