 Electromagnetic EM pollution is a major concern for electronic devices and biological systems. Therefore, novel materials with EM absorption properties can solve this problem. Porous carbon, PC, materials are promising EM absorbers due to their ultra-low density, large surface area, and excellent dielectric loss ability. However, the large-scale production of PC materials through simple synthetic root is not feasible. Here, we introduce a biomass-derived EM absorber material with a promising performance and low-cost production process. The EM absorption is mainly influenced by the structure, such as hierarchical texture, periodic pattern, and some unique nanoarchitecture. The synthetic process is based on the optimization of structure and designing composition, which can lead to versatile and low-cost materials with a wide application. This article is authored by Huang Qinjiao, Yan Cheng, Wei Lu, and others.