Abstract: Gas separation membrane technology, as a key gas separation method to achieve carbon neutrality, has made significant progress in the field of carbon dioxide capture, Mixed matrix membrane (MMM) combines the advantages of polymer membranes and porous fillers, making it an effective alternative to conventional polymer membranes. However, interface incompatibility issues limit MMM's gas separation performance. In Membrane separation technology, MMM prepared by introducing a third component (usually a functional additive) can effectively overcome the structural problems of binary phase MMM and have a positive impact on the separation performance of the membrane. This review focuses on the preparation process of ternary phase MMM using Ionic Liquid (IL) and Metal-Organic Framework (MOF) as high efficiency fillers, and further analyzes the synergistic effect of integrating IL and MOF into MMM. In particular, they contribute significantly to improving the mechanical stability and gas adsorption properties of membrane materials. In this paper, the transport mechanism of gas separation in MMM is introduced in detail, the structure and preparation process of IL/MOF composites are summarized, and the CO₂ separation performance of ternary phase MMM is reviewed and analyzed in detail. Based on these separation performance data, the challenges faced by ternary phase MMM are further discussed, which provides new ideas and directions for the development of membrane separation technology in the future.