Abstract: The Fe₃O₄ loaded ceramic composite microwave absorbents were successfully prepared by recycling the solid waste coal gangue. First, the coal gangue based matrix was obtained by crushing, ball-milling, acid pickling, granulation and sintering process, and then the subsequent experiment involved loading precursor solution as well as in-situ carbothermal reduction. Moreover, the influence of Fe₃O₄ loading content on the microstructure and electromagnetic performance was also investigated. It was founded that the ceramic composites exhibited excellent microwave absorption when the reduction temperature kept 600 ℃ and the concentration of precursor solution was 1.25−1.5 mol/L, under which the minimum reflection loss value reached −20.1 dB and the effective absorption bandwidth kept 4.7 GHz as the coating thicknesses was 2.0 mm. This was attributed to the better impedance match and attenuation characteristic. The simple technological process provided in this work could offer a novel method for the recycling of coal gangue, and was beneficial for the low-cost of microwave absorbents.