The CG combined aeration impeller is a stirring system that combines the GXJ self-priming aeration impeller and the PJT turbine impeller. It simultaneously features high gas velocity dispersion and internal gas circulation in a pure gas-liquid reaction system. The combined gas impeller system promotes the conversion of mass transfer-limited reactions. Unconverted gas from the top of the vessel is recycled into the reaction medium, ensuring complete utilization of the reaction gas.