Abstract: To solve the problems of narrow effective microwave absorbing bandwidth and poor absorption strength of Y₂Ti₂O₇ nano materials, a flower-like CoNi/C loaded Y₂Ti₂O₇ composite microwave absorbent was prepared by the solvothermal method. The phase structure and microstructure of the samples were tested by XRD and SEM. The results show that the flower-like structure is composed of flaky CoNi/C, and there is a porous structure on the flaky structure. By adjusting the relative content of CoNi and Y₂Ti₂O₇, a series of CoNi/C/Y₂Ti₂O₇ composites with different impedance matching and microwave absorbing properties has been prepared. When the mass of CoNi alloy accounts for 60% in the composite, the best microwave absorbing performance is achieved. When the thickness of the coaxial ring is 1.8 mm, the effective wave absorbing bandwidth reaches the widest 4.64 GHz and the reflection loss is −30.75 dB. As the thickness increases to 2.3 mm, the optimal reflection loss is −41.95 dB at 12.08 GHz and the effective wave absorbing bandwidth is 4.14 GHz. The preparation of the composite provides a reference for developing new lightweight and high-performance microwave absorbing materials.