Display omitted •MOFs-based MMMs materials for CO2 separation are systematically reviewed;•The non-ideal interface is the key obstruct for fabricating MMMs;•Advanced characterizations of the non-ideal interface are summarized;•Interfacial regulation is deconstructed as architecting single or multiple interfaces;•Several prospects for the defect-free MMMs are put forward. Due to the characteristics of simplicity, efficiency, adaptability and eco-friendly, membrane separation technology has been widely considered to play an important role in CO2 separation. Mixed matrix membranes (MMMs) combined advantages of various components have attracted masses of attention, providing a potential possibility for the large-scale popularization and application of membrane separation technology. Metal organic frameworks (MOFs) are considered as ideal candidates to fabricate defect-free MMMs. However, the further application of MMMs was seriously hindered due to the non-ideal interface between MOFs and polymer matrix. The review focused on the interfacial structure between MOFs and polymer in MMMs for CO2 separation. The interfacial optimization in MMMs was deconstructed into single enhancement of filler-polymer and multiple transitions of filler-extra phase-polymer. The prospects and potential problems of interfacial formation and advanced characterization of MOFs-based MMMs were discussed. Finally, the prospects and challenges for ultrathin and defect-free MMMs fabrication were outlined. This review will offer some inspiration for the fabrication of high-performance MMMs for CO2 separation from the point of view of non-ideal interfacial regulation.