Aerogel is a solid material with the smallest density and lightest weight in the world at present. Its unique three?dimensional network structure makes it widely used. Cellulose aerogels not only have the characteristics of high porosity and high specific surface area of aerogels, but also can be degraded by microorganisms and be compatible with other substances, which is a new energy suitable for sustainable development. The preparation process of cellulose aerogel—sol gel process and hydrogel drying process are described. In addition, the applications of cellulose aerogel in oil?water separation, heat insulation, phase change, supercapacitor, biomedicine and other aspects are also introduced, and its development is prospected.