A hierarchical architecture of Ti3C2/Fe3O4/PANI composite as a high-efficiency microwave absorber was synthesized using HF etching, coprecipitation and in-situ polymerization route. Layered Ti3C2 was used as a matrix material with high surface area and a network offering more paths of electron transfer. The adding of PANI and Fe3O4 can generate an outstanding microwave absorption property because of enhanced interfacial polarization, strong attenuation loss and excellent impedance matching. The hierarchical Ti3C2/Fe3O4/PANI ternary composite shows a strongest reflection loss (R-L) of -40.3 dB at 15.3 GHz, which is higher than those of Fe3O4 and Ti3C2/Fe3O4. Furthermore, it also displays broad absorption frequency band, possessing the efficient absorption bandwidth (< -10 dB) of 5.2 GHz (from 12.8 to 18 GHz) at only 1.9 mm. The improving microwave absorption performances may be ascribed to hierarchical structure and synergistic effect of combining Ti3C2, Fe3O4 and PANI. The results of this work provide a new idea of utilizing Ti3C2 matrix to prepare 3D hierarchical composite for the applications of MXene family in microwave absorption fields.