Abstract: The NiO/CeO₂ catalytic materials were prepared with ball milling method using CeO₂ as carrier and Ni as active component with good CO oxidation performance at low temperature. The catalysts were characterized by XRD, BET, H₂-TPR, XRF and XPS. The effects of nickel content on the structure and low temperature oxidation performance of CO were investigated. The results show that the Ni-Ce ratio mainly affects the number of lattice oxygen vacancies and the interaction between the active ingredient and the carrier. Among them, When the Ni/Ce mole ratios is 1∶9, there are more oxygen vacancies on the surface of the catalyst, so it shows excellent catalytic performance. When the reaction temperature is 200 ℃, oxygen excess coefficient is 5 and the total space velocity is 60000 mL/(g_cat·h), the CO conversion reaches 99.2%. In addition, compared with the traditional liquid phase catalyst preparation technology, ball milling has the advantages of low pollution, low cost and easy operation, which is beneficial to save energy.