A series of 2,4-dihydroxybenzoates {(2,4-DHB) n Ms, M = Pb(II), Cu(II), Fe(III), Ni(II) and Co(II), n = 2 or 3} micro-nano spheres with controllable size and morphology were successfully prepared by spray drying method with water or acetone as a solvent. TEM and SEM illustrated that the (2,4-DHB) n Ms micro-nano spheres had core–shell or solid structure. The formation of the core–shell structure of the samples was interpreted in terms of the mechanism of spray drying. The results of laser particle analyzer revealed that precursor concentration (PC) and particle size distribution (PSD) of the samples were well fitted with power function. The thermal decomposition of ammonium perchlorate (AP) in the presence of the (2,4-DHB) n Ms micro-nano spheres, investigated by differential scanning calorimetry (DSC), showed they effectively lowered the decomposition temperature of AP and exhibited various catalytic performance for AP decomposition.