Silicone shows an excellent performance of thickening CO2 and becomes a well-known CO2 thickener due to the low price and environmentally friendly. Siloxane copolymers could be synthesized via the copolymerization and other reactions. Optimal preparation parameters were temperature 90 degrees C, the aminopropyltriethoxysilane-to-methyl triethoxysilane molar ratio of 2:1, the amount of catalyst 0.09g. The yield of production coordinated well with the predicted yield of 83.72%. The structure of production is analyzed by FTIR. Adding 3% w.t. 7.2 order of magnitude could be realized at 0.3mLmin(-1) flow rate by using the silicone present at concentrations of 3wt% at 35 degrees C and 12MPa. Moreover, Greenhouse effect could be improved due to the application of CO2 fracturing.