Abstract: Disclosed are a preparation method for a SiO2 aerogel and a SiO2 aerogel, and belongs to the technical field of chemical coatings. The preparation method for the SiO2 aerogel comprises the following steps: S100: uniformly mixing an inorganic silicon source, water, a surfactant and an acid catalyst, and gelating the mixture to obtain a wet gel; S200: uniformly mixing a surfactant, a cosolvent and a low-surface-tension solvent to obtain a reverse micelle extraction solution; S300: mixing the wet gel obtained in the step S100 with the reverse micelle extraction solution obtained in the step S200, and soaking the mixture to obtain a gel; and S400: drying the gel obtained in the step S300 to obtain the SiO2 aerogel.