［Objective］In order to improve the optical transmittance and antifogging property of glass.［Methods］On the basis of analyzing the influence of thickness on optical properties by usingTFCalc optical film design software，SiO₂ antireflection films were prepared on BK7 glass by an acid-catalyzed sol-gel method. The structure and surface morphology of the SiO₂ film were characterized by X-ray diffraction（XRD）， scanning electron microscope（SEM） and white light interferometer. The transmittance spectra of SiO₂ films with different incident angles（0°，15°，30°）were tested using a UV-visible-near-infrared spectrophotometer. The contact angle was measured and its variation with solid-liquid contact time was recorded. The wettability of the film was analyzed and the antifogging propertyof SiO₂ film was evaluated through a self-made anti-fog testing device.［Results］The results indicated that SiO₂ prepared by acid catalyzed sol-gel method was amorphous phase. The SiO₂ films prepared on BK7 glass was uniform and crack-free. Compared to uncoated glass，the surface roughness of the SiO₂-coated glass was significantly higher. All the SiO₂ films prepared on BK7 glass had antireflection property. Among them，the average transmittance of SiO₂ film prepared on BK7 glass with the pullingspeed of 3 cm/min was 93. 39% at the wavelength of 380-1 100 nm，which was 1. 62% higher than that of the uncoated glass. When the incident angle increased from 0° to 30°，the transmittances of BK7 glass with and without SiO₂ film were decreased. However，at an incident angle of 30°，the SiO2 film prepared on BK7 glass with the pulling speed of 3 cm/min exhibited an average transmittance of 90. 89%，which was 2. 42% higher than that of the uncoated glass. The water contact angle of BK7 and SiO₂-coated BK7 glass were about 47° and 3°，respectively，indicating that the SiO₂ film had superhydrophilicity. Antifogging tests showed that the SiO₂ film coated on BK7 glass had good antifogging performance.［Conclusion］All the results illustrated the SiO₂ films prepared on glass byacid-catalyzed sol-gel method had both antireflection and antifogging properties.