Abstract: A three-dimensional structure MnO₂@NiCo₂O₄@Ni-foam composite with NiCo₂O₄ nanowires as core and MnO₂ nanoparticles as shell was prepared by two-step hydrothermal method. The structure and morphology of the composite catalyst were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Cyclic voltammetry (CV), constant current charge and discharge performance (GCD) and electrochemical impedance spectroscopy (EIS) were performed. The electrochemical performance of the composite was characterized and the catalytic performance of the composite by ozone catalytic degradation device was investigated. The results showed that the MnO₂@NiCo₂O₄@Ni-foam composite had lower impedance in the frequency range of 0.1-10 000 Hz. It was found by degradation experiments that the degradation rate of MnO₂@NiCo₂O₄@Ni-foam to ozone was higher than 50%, showing good catalytic effect, which indicated that MnO₂@NiCo₂O₄@Ni-foam composite had broad application prospects in degrading ozone and purifying air.