Abstract: The method resides in that silicon tetrafluoride is subjected to water hydrolysis in the presence of sulphuric acid, the reactants being in an aerosol state.Hydrolysis is performed at a volume ratio of silicon tetrafluoride to sulphuric acid equal to 40:1-80:1, concentration of sulphuric acid within the range of 45-73 wt. %, and the rate of silicon tetrafluoride flow in the reaction zone of 0.2-4.0 m/sec. The process is run at room temperature and atmospheric pressure.As a result of hydrolysis, silicon dioxide and fluorine-containing sulphuric acid solution are obtained, hydrogen fluoride being extracted from the solution upon heating.The proposed invention makes possible an effective use of silicon tetrafluoride with maximum conversion of the components thereof into end products, separation of the end products taking place simultaneously with the formation thereof. The yield of the products reaches 92-95 wt. % of their content in the initial raw material.