Mixed matrix membranes (MMMs) prepared from fillers and polymer matrices have attracted great attention in the field of CO2/CH4 separation. MMMs not only retain the characteristics of inorganic membranes, such as heat resistance, chemical resistance, high permeability, and selectivity, but also combine the advantages of pure polymer membranes, such as low cost, easy operation, and easy production. In this paper, the latest progress of MMMs in CO2/CH4 separation is discussed: ① Three gas separation mechanisms are introduced; ② Special attention is given to the application of carbon nanotubes (CNTs), graphene oxide (GO), metal-organic framework materials (MOFs) and zeolite materials in MMMs for CO2/CH4 separation; ③ The future development direction of MMMs in the field of CO2/CH4 separation is proposed.