Bio-mass materials have been selected as one of the advanced electromagnetic (EM) functional materials due to their natural porous framework for dynamically and flexibly optimizing the EM response property. Herein, we demonstrate sulfur-doped wood-derived porous carbon EM materials (SPC) for optimizing the EM response performance via the coupling between doped heterostructures and the original 3D microchannels. The experimental results reveal that both the dielectric loss capacity and interfacial impedance matching could be increased by the sulfur-doped heterostructures. By tailoring the sulfur content, the microwave absorption (normalized RLmin) of SPC could be optimized to -15.90 dB mm-1, while the effective absorption bandwidth (EABRL≤-10 dB) could cover the K band. Moreover, the shielding effectiveness of SPC can be enhanced from 10 dB to 30 dB with the assistance of water, ascribed to the super-wettability performance. This present study provides a novel strategy to further optimize the EM response performance of wood-derived materials, and meanwhile could be widely extended to other bio-mass absorbers.