Flower-like NiCo₂O₄ wave absorbing material was prepared by the co-precipitation method. The composition and structure of NiCo₂O₄ was characterized by XRD， FTIR， BET， XPS and SEM. The samples were synthesized under various calcination temperature （300，400，500，600，700 ℃）， and the wave-absorbing properties of the samples were calculated depend on vector network analyzer （VNA） by coaxial method with different thickness. The results show the NiCo₂O₄ calcinated at 400 ℃ exhibits superior electromagnetic wave attenuation performance in reflection loss value， absorption bandwidth and thickness of sample. The effective absorption bandwidth of flower-like NiCo₂O₄ is 4.48 GHz （12.08~16.56 GHz） at the thickness of 1.5 mm. Moreover， The minimum reflection loss of flower-like NiCo₂O₄ reach to -43.71 dB at the 14.32 GHz. Hence， it is evident that NiCo-based spinel oxide material is anticipated to possess a potential implication in the field of electromagnetic wave absorption.