The flower-like precursor (CH3O)2Co microspheres assembled by nano-flakes were firstly fabricated by a solvothermal method using Co(Ac)2 as source materials in methanol system. Co3O4 porous microspheres with well-preserved morphologies were then achieved by calcining the precursor. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetry (TG), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and N2 adsorption-desorption were used to characterize the phase, chemical composition, morphology and pore structure of the samples. Differential scanning calorimetry (DSC) was employed to evaluate the catalytic performance of these Co3O4 microspheres for thermal decomposition of ammonium perchlorate (AP). The result shows that the as-obtained Co3O4 microspheres exhibit excellent catalytic performance. Adding 2% (wt) Co3O4 microspheres into AP decreases the high-temperature exothermic peak by 122 癈 and the apparent decomposition heat increases by 422 J/g, respectively. The excellent catalytic activity is attributed to good dispersities and plentiful hierarchical pore structure of Co3O4 microspheres.