Ti3C2Tx MXene is an excellent electromagnetic wave (EMW) absorber with excellent electrical conductivity and abundant surface functional groups. In this research, Ti3C2Tx/TiO2/PANI multi-layer composites were successfully synthesized by HCl and LiF etching, one-step hydrothermal method and in-situ polymerization. Ti3C2Tx can provide more electron transfer paths due to its unique multilayer structure and high specific surface area. The growth of TiO2 particles on the surface of Ti3C2Tx through hydrothermal reaction enhances the interface polarization, and then polyaniline (PANI) is doped on the surface of Ti3C2Tx where TiO2 particles are grown by in-situ polymerization. Due to the excellent dielectric properties and synergistic effects of the material itself, Ti3C2Tx/TiO2/PANI composites have excellent EMW absorption property. In this study, the Ti3C2Tx/TiO2/PANI composites showed the strong reflection loss (RL) of at 13.92 GHz, which was-65.61 dB, and the thickness was only 2.18 mm. Moreover, the composites also exhibit a wide absorption band, with an effective absorption bandwidth (RL <-10 dB) of 5.92 GHz (11.84 GHz to 17.76 GHz) at 2.10 mm. The results show that the Ti3C2Tx/TiO2/PANI composites are expected to become EMW absorber with thin thickness and high absorption strength. (c) 2020 Elsevier Inc. All rights reserved.