This work aims to improve the catalytic activity of energetic Pb(II) complex of 2,6-diamino-3,5-dinitropyridine-1-oxide (Pb-ANPyO) on the thermal decomposition of ammonium perchlorate (AP). The Pb-ANPyO nanoparticles with a size of approximate 20 nm were successfully deposited on the surface of carbon nanotubes (CNTs) via chemical precipitation method, which exhibited a lower decomposition temperature than that of normal-sized Pb-ANPyO. The catalytic performance of Pb-ANPyO and Pb-ANPyO/CNTs nanocomposites on the thermal decomposition of AP were fully evaluated by thermogravimetry-differential scanning calorimetry TG-DSC, non-isothermal kinetics and -T kinetic curves measurements and analyses, respectively. The results showed that Pb-ANPyO/CNTs nanocomposites exhibited higher catalytic activities than that of Pb-ANPyO on the thermal decomposition of AP due to the synergistic effect of the CNTs and Pb-ANPyO nanoparticles. During the thermal decomposition process of AP catalyzed by Pb-ANPyO/CNTs nanocomposites, PbO/CNTs nanocomposites might be formed in situ and acted as the real catalyst with high catalytic activity, which promoted the thermal decomposition of AP.