Abstract: Using cerium nitrate as the source material and urea as the precipitant, nanometer CeO₂ carrier was prepared by hydrothermal method, and the microstructure of CeO₂ carrier was controlled by changing the hydrothermal reaction temperature. Then the CuO/CeO₂ catalytic material was prepared by loading CuO on the CeO₂ carrier and evaluated in methanol steam reforming for hydrogen production. Based on the characterization data of low temperature nitrogen adsorption, XRD, H₂-TPR and XPS, the effects of hydrothermal reaction temperature on the microstructure of CeO₂, the structure of CuO/CeO₂ catalytic material and the performance of methanol steam reforming were investigated. The results show that the nanometer CeO₂ support prepared at 180 ℃ has a cubic fluorite structure. After loading CuO onto the CeO₂, the obtained CuO/CeO₂ catalyst exhibits better catalytic activity due to its stronger Cu-Ce interaction, lower reduction temperature of Cu species in the surface, and more oxygen vacancies on the surface of the catalyst. When the reaction temperature is 280 ℃, the molar ratio of water to alcohol (W/M) is 1.2, and the space velocity of methanol vapor gas (GHSV) is 800 h^{− 1}, the methanol conversion rate can reach 91.0%, the mole fraction of CO in reforming gas is 1.29%.