Abstract: There are pores of different shapes, sizes and arrangements in the microstructure of SiO₂ aerogel.These pores can form small channels, protrusions, depressions and other complex forms, which have the characteristics of large specific surface area and high porosity.SiO₂ aerogels are widely used in many fields.Due to its low density and high porosity properties are applied to sound absorption materials, low thermal conductivity is widely used in thermal insulation materials, and with its porosity, high specific surface area and other structural characteristics, it can efficiently adsorb and remove pollutants in sewage, and also show good application prospects in sewage treatment.Four stages for preparing SiO₂ aerogels were reviewed in this paper, including preparation of wet gel by sol-gel method, aging of gel, surface modified and drying of SiO₂ aerogel, and their characteristics of each stage were summarized.The adsorption application of silica aerogel in organic dye containing, oily and heavy metal ion containing wastewater was highlighted, and its future development trend was prospected.