Nowadays, metal oxide-based electromagnetic wave absorbing materials have aroused widely attentions in the application of telecommunication and electronics due to their selectable mechanical and outstanding dielectric properties. Herein, the binary ZnO/NiCo₂O₄ nanoparticles were successfully synthesized via hydrothermal reaction and the electromagnetic wave absorption properties of the composites were investigated in detail. As a result, benefiting from the dielectric loss, the as-obtained ZnO/NiCo₂O₄-7 samples possessed a minimum reflection loss value of -33.49 dB at 18.0 GHz with the thickness of 4.99 mm. This work indicates that ZnO/NiCo₂O₄ composites have the promising candidate applications in electromagnetic wave absorption materials in the future.