Double-layer absorbers with enhanced microwave absorbing properties were designed based on polyaniline and polyaniline/magnetite composite with a total thickness of 1mm. The double-layer microwave absorbers have better microwave absorbing properties than those of single-layer microwave absorbers, and the microwave absorbing properties of the double-layer structure are influenced by the coupling interactions between the absorbing layer and matching layer. When the absorbing layer is PANI with a thickness of 0.4mm, and the matching layer is PANI/Fe3O4 composite with a thickness of 0.6mm, the minimum reflection loss (RL) reaches −42dB at 29.27GHz and the absorption bandwidth with RL below −10dB is about 11.8GHz. While when PANI and PANI/Fe3O4 composite are acted as matching layer and absorbing layer, respectively, with the same thickness of 0.5mm, a minimum RL value of −54dB is observed at 33.72GHz and the absorption bandwidth is about 11.28GHz ranging from 27.24 to 38.52GHz with the RL value below −10dB.