This study investigates the preparation and wave absorption properties of NiCo/NPC composites. The NiCo-MOF-74, synthesized via a solvothermal method, serves as the precursor for the composite. The Ni/Co molar ratio is varied to optimize the morphology, graphitization degree, magnetic properties, and wave absorption properties of the composites. The results show that increasing the Co content enhances the graphitization of the carbon component, leading to improved ferromagnetic properties. The wave absorption properties of the NiCo/NPC composites initially increase and then decrease with increasing Co content. Optimal wave absorption is achieved at a Co content of 50% (mass fraction) and a Ni/Co molar ratio of 1:1. The Ni$_1$Co$_1$/NPC composite exhibits a maximum reflection loss of −50.8 dB at 16.96 GHz with a thickness of 2 mm and an effective absorption bandwidth of 4.56 GHz (13.44–18 GHz). The study highlights the potential of NiCo/NPC composites as effective electromagnetic wave absorption materials.This study investigates the preparation and wave absorption properties of NiCo/NPC composites. The NiCo-MOF-74, synthesized via a solvothermal method, serves as the precursor for the composite. The Ni/Co molar ratio is varied to optimize the morphology, graphitization degree, magnetic properties, and wave absorption properties of the composites. The results show that increasing the Co content enhances the graphitization of the carbon component, leading to improved ferromagnetic properties. The wave absorption properties of the NiCo/NPC composites initially increase and then decrease with increasing Co content. Optimal wave absorption is achieved at a Co content of 50% (mass fraction) and a Ni/Co molar ratio of 1:1. The Ni$_1$Co$_1$/NPC composite exhibits a maximum reflection loss of −50.8 dB at 16.96 GHz with a thickness of 2 mm and an effective absorption bandwidth of 4.56 GHz (13.44–18 GHz). The study highlights the potential of NiCo/NPC composites as effective electromagnetic wave absorption materials.