Abstract: In order to improve the increasingly serious electromagnetic pollution caused by the rapid development of communication and electronic devices, and solve the problems of complicated preparation methods and high energy consumption of magnetic carbon-based absorbing materials, this project proposes a new method for developing iron-based carbon fiber absorbing materials. Using hollow poplar catkin fibers as carriers, Fe³⁺ as the metal source, and wet chemical adsorption and high-temperature carbon thermal reduction methods, Fe-Fe_xO_y/C composite materials with excellent microwave absorption properties were obtained. The experimental results show that as the calcination temperature increases, different iron oxides (Fe/Fe₃O₄/FeO) are generated by combining the iron component with oxygen-containing groups in the Yangxu fibers, and the coercivity and saturation magnetization of the material are enhanced, and the ferromagnetic properties are obvious. Fe-Fe_xO_y/C-600 has the best absorption performance, and the effective absorption bandwidth can reach 8.4 GHz (7.2-15.6 GHz) when the thickness of the absorber is 3 mm. The excellent absorption performance of the composite material is attributed to the synergy of impedance matching and dielectric loss and magnetic loss, and the mutually carried fiber structure builds a suitable attenuation space for electromagnetic waves and quickly attenuates in the carbon fiber conductive network. The research will provide reference for the design and development of new iron based carbon fiber absorbing materials.