As a kind of ordered solid solution, γ′-Fe4N exhibits enormous potential in improving electromagnetic wave absorption performance profiting from stable chemical properties, high conductivity and saturation magnetization. In this work, nitrogen-doped carbon fibers embedded with Fe4N nanospheres were prepared by electrospinning process and gas nitridation engineering to accomplish high-efficiency, broad-bandwidth and thin-thickness microwave absorption. In particular, the influence of intrinsic electronic structure, magnetic phenomena caused by time effect of dynamic magnetization, and anisotropic microscopic texture on attenuation competence and impedance matching characteristics were deeply analyzed. Satisfyingly, γ′-Fe4N@nitrogen-doped carbon fibers (Fe4N@NCFs) conferred a minimum reflection loss of − 77.7 dB at 2.0 mm and a maximum effective absorption bandwidth of 5.8 GHz at 1.8 mm. Furthermore, Fe4N@NCFs displayed broad designability and promising application potential when participated in the design of waste energy secondary utilization device and electromagnetic stealth antennas. This study profoundly delineated the inherent mechanisms of Fe4N-based absorber and shed light on the functional development and exploitation of materials.