Abstract: A series of Cu/Zn/Al/Si slurry catalysts were prepared by the complete liquid-phase technology with acid and alkaline silica sol in the paper. The catalysts are characterized by means of XRD, H₂-TPR, FT-IR, BET, NH₃-TPD, XPS and TEM. When the acid silica sol is added, which has the similar environment with the process of precursor preparation, the conversion of CO and selectivity of dimethyl ether reach maxiumum, being 65.38% and 76.26% respectively. The acid silica sol weakens the force between Cu and other components, resulting in the Cu component is easy to be reduced and more active lattice planes of Cu⁰ on the catalyst are exposed. The acid/alkaline properties of silica sol influence acid site strength and the number of acid sites of catalysts and make both strong acidic sites and the weak acidic sites migrate to lower temperature position. In DME synthesis reaction, it is found that the acid silica sol can increase the ratio of the weak acidic sites to the strong acidic sites on the catalysts, which promotes dehydration performance of methanol and the selectivity of DME. In addition, the catalysts with large specific surface area and mesoporous pore structure are favorable for the activity and selectivity of DME.