Abstract: The traditional composites experience degradation in electromagnetic interference shielding efficiency (EMI SE) due to the fracture of conductive structures during deformation. Therefore, in order to significantly improve the electromagnetic shielding stability of the elastic material, in this study, a 3D conductive network is constructed in polydimethylsiloxane (PDMS) composites by designing dynamic conductive interfaces. Firstly, the NMXene nanosheets with different surface charge were prepared by surface-modifying MXene. Subsequently, the NMXene and MXene nanosheets were sequentially electrostatically adsorbed on the surface of thermal expansion microspheres (TEMs) for preparing the composite microspheres (TEMs@NMXene-MXene, TNM) with a dynamic conductive shell (NMXene-MXene). After the recombination of the composite microsphere and PDMS matrix, TNM/PDMS-30 composite was obtained by precisely controlling the thermal expansion time as 30 min. The dynamic electrostatic adsorption among TEMs, NMXene and MXene can promote the formation of stable 3D conductive network, which effectively shields the electromagnetic waves and rapidly consumes electromagnetic energy through multiple reflections. Thus, TNM/PDMS-30 composite containing 5wt% conductive components (NMXene and MXene) achieves an EMI SE of 37.0 dB in X-band and remains a shielding efficiency of 30.2 dB at 50% tensile strain. In addition, TNM/PDMS-30 exhibits excellent superelasticity, tensile strength (8.02 MPa) and elongation at break (149.5%), which provides new ideas for the application in the field of flexible electromagnetic shielding materials.