In order to obtain the composite gel with excellent performance in the supercritical CO₂ state，through the L16（44）orthogonal experiment，the influence of CO₂ pressure，reaction temperature，reaction time and sodium silicate concentration on inorganic gel production were studied. Under the condition of supercritical CO₂，the inorganic and organic composite gel system was prepared from the mixture of sodium silicate solution and acrylamide，the microscopic structure of inorganic gel，organic gel， composite gel was observed through the environmental scanning electron microscopy（ESEM） . The results showed that，The appropriate conditions of inorganic gel were as follows，the reaction pressure was of 9.0 MPa，the reaction temperature was 32.0℃，the reaction time was 14.0 h and the sodium silicate mass fraction was 4.0%. In supercritical CO₂，inorganic gel particle equably dispersed in organic gel network structure，which was beneficial to enhance the strength of the composite gel.