CuO/Bi2O3 particle catalyst was prepared by homogeneous precipitation in the hydrothermal system. Effects of hydrolysis pH on the crystalline precipitate were studied and optimal calcination temperature was obtained with TG analysis results. The structure, morphology and specific surface area of the particles were characterized with XRD, SEM and BET techniques, and the results showed that perfect crystal , larger surface area and a average size of 0.1-0.5 μm powder particles could be obtained when calcination temperature was 400 oC. It was proved that the compound oxide catalyst CuO/Bi2O3 had a good catalytic effect on the ethynylation reaction. Factors such as contents of Bi, reaction temperature, partial pressure of acetylene, and pH of solution on the catalytic activity were studied, and a 21.10% yield of 3-Hexyne-2,5-diol was got under the optimized reaction conditions: Bi content 12%; Temperature 120 oC; pH≈6-7; The acetylene partial pressure 1.0 MPa.