The widespread use of electronic devices significantly facilitates daily human life, but also leads to increasingly serious electromagnetic pollution. Therefore, it is necessary to develop eco-friendly electromagnetic interference (EMI) shielding materials with excellent overall performance. Here, we prepare a waste paper/biocarbon (WP/BC) composite with a distinct densely self-bonded core-shell structure through the partial dissolution co-mixing process. Benefiting from this structure, the WP/BC composite exhibits metal-grade EMI shielding performance of EMI shielding effectiveness (EMI SE) up to 69.59 dB and superior flame retardancy (limiting oxygen index of 33.39 %). In addition, the WP/BC composite also shows favorable thermal management performance and low environmental impacts. This lightweight and eco-friendly WP/BC composite with excellent overall performance possesses significant potential for applications in commercial, industrial, and military sectors.