Mixed matrix membranes (MMMs) with easy scale-up architectures have shown great potential to achieve superior CO₂ permeance, while their performances are often restricted by the poor interfacial compatibility between fillers and the matrix, and also by blocking of the original channel for gas transmission. Here, a rational design and facile construction of highly permeable MMMs is presented by dispersing triphenyltriazine-based β-ketoenamine-linked covalent organic framework (TpTta-COF) within solution-processable polymer of intrinsic microporosity (PIM-1). An intimate mixing was achieved by improved compatibility of the components induced by the hydrogen bond interaction between -N-H in TpTta-COF and CN of PIM-1. The good adhesion avoids the formation of interface defects, preserving the original gas transmission channel. TpTta-COF particles with strong CO₂ affinity are evenly distributed in the matrix, forming a fast and continuous channel for CO₂ transmission. The physical properties of MMMs were easily tuned, and the as-prepared PIM-1/TpTta–COF–6wt% demonstrates extraordinary stability, high CO₂ permeability and CO₂/N₂ selectivity, surpassing the β-ketoenamine-free MMM counterparts. This study provides a feasibly pathway for the development of efficient and high performances separation membranes.