CuO-ZnO-Al2O3 is a typical catalyst for methanol synthesis from CO2 hydrogenation.CuO-ZnO-Al2O3 was modified with SiO2 which was hydrolyzed from tetraethyl orthosilicate (TEOS), using co-precipitition method.The promoted catalysts were tested under the conditions of 200 ℃, 2.4 Mpa, H2∶CO2=3∶1 (volume ratio), SV=3600 h-1.Results show that the promoted samples are better than the CuO-ZnO-Al2O3, and 2 wt.% is the optimal dosage with CO2 cony.improvement by 48.68% and CH3OH yield by 39.86%, respectively.XRD, CO2-TPD, H2-TPD, H2-TPR and FT-IR characterizations were performed, and results showed SiO2 improved the CuO dispersion in the catalyst, enhancing the adsorption/activation of CO2 and H2 on the catalyst, and promoting the intermediate species such as formates and carbonates, made the active component CuO be reduced more easily.