Polyamide (PA) membranes, prepared by facile and scalable interfacial polymerization (IP), have the potential to serve as candidates for large-scale CO2 capture from flue gases in power plants. However, current PA-based membranes exhibited limited CO2 separation performance, restricting their large-scale uses. Herein we developed an ionic liquid (IL)-mediated IP process for fabricating novel PA-based heterogeneous facilitated transport membranes (HFTMs) for efficient CO2 capture. During the IP process, IL regulated and modified the gas transport channels within the PA matrix to accommodate the mobile CO2 carrier, namely IL itself. Owing to the negatively charged PA matrix and facilitated transport feature, PA/IL (PAIL) membranes exhibited superior and stable CO2 permeance up to 1,050 GPU and CO2/N2 selectivity up to 300 under simulated flue gas separation conditions. The selectivity of these PAIL membranes is one order of magnitude higher than reported polymeric membranes with similar CO2 permeance and capable of enriching CO2 from 15% to 97% in one step. Given the one-step, facile membrane preparation via IP technology, this work may open a new field of synthesizing ultrathin, highly selective HFTMs in a practical and scalable way for highly efficient gas separation applications.