The employment of microwave absorbents is highly desirable to address the increasing threats of electromagnetic pollution.Importantly,devel-oping ultrathin absorbent is acknowledged as a linchpin in the design of light-weight and flexible electronic devices,but there are remaining unprecedented challenges.Herein,the self-assembly VS4/rGO heterostructure is constructed to be engineered as ultrathin microwave absorbent through the strategies of architecture design and interface engineering.The microarchitecture and het-erointerface of VS4/rGO heterostructure can be regulated by the generation of VS4 nanorods anchored on rGO,which can effectively modulate the imped-ance matching and attenuation constant.The maximum reflection loss of 2VS4/rGO40 heterostructure can reach-43.5 dB at 14 GHz with the impedance matching and attenuation constant approaching 0.98 and 187,respectively.The effective absorption bandwidth of 4.8 GHz can be achieved with an ultrathin thickness of 1.4 mm.The far-reaching comprehension of the heterointerface on microwave absorption performance is explicitly unveiled by experimental results and theoretical calculations.Microarchitecture and heterointerface synergistically inspire multi-dimensional advan-tages to enhance dipole polarization,interfacial polarization,and multiple reflections and scatterings of microwaves.Overall,the strate-gies of architecture design and interface engineering pave the way for achieving ultrathin and enhanced microwave absorption materials.