Exploration of lightweight and thin electromagnetic (EM) wave absorption materials is still urgent because of the issues related to EM pollution. In this work, one-dimensional core-shell nanowires with Co nanoparticles embedded in N doped porous carbon (Co@NPC NWs) have been successfully fabricated for microwave absorption. The obtained Co@NPC composites with a pea-like structure have high loading of Co nanoparticles (68 wt%) encapsulated by the defective carbon shell. Thanks to these special characteristics, the Co@NPC NWs exhibit superb microwave absorption properties in comparison with the pristine nano-Co powder and NPC. The strong reflection loss (RL) of -48 dB could be achieved at a thickness of only 1.45 mm. In addition, the effective absorption bandwidth is up to 5.2 GHz. These superb absorption properties coupled with thin thickness endow the Co@NPC NWs with great potential for application in lightweight EM wave absorption.