This paper is to prepare hybrid composite absorbing coating with good absorbing properties. Carbon black and carbonyl iron powder are mixed mechanically and added into epoxy resin as absorbent for the preparation of absorbing materials. The microstructure of carbon black and carbonyl iron powder is observed by scanning electron microscope. The electromagnetic properties are tested by vector network analyzer in 2~18 GHz. The effects of carbon black and carbonyl iron powder content and the coating thickness on the absorbing properties are studied. By observing the microscopic morphology, it is found that the carbon black particles are small, appearing agglomeration and adhesion phenomenon, while the carbonyl iron powder particles are spherical, the surface is smooth, good dispersion. The composite material mixture is more uniform, the carbonyl iron powder dispersed in the matrix with carbon black group can improve the absorbing performance of the material; The absorbing frequency band of pure carbon black is narrow, and that of pure carbonyl iron powder is mainly concentrated in the middle and high frequency band, while the absorbing frequency band of composite is wider, which has good absorbing performance. When the content of carbon black is 4%, carbonyl iron powder is 250%, and the thickness of the absorbing coating is 2 mm, the absorption rate of the coating is more than 90% in the range of 9~18 GHz, and the peak value of reflection loss is nearly –45 dB. The composite material of carbon black and carbonyl iron powder has wider absorbing band and better effect, which solves the problems that single absorbing agent coating is narrow absorbing band and concentrated in high frequency band. By adjusting the coating thickness, the material can obtain better absorption performance in the corresponding band, so it can be used more widely.