Nanocomposite CuO·PbO with different Cu/Pb mass ratio was prepared by solid state reaction method at room temperature using CuCl₂·2H₂O and Pb(NO₃)₂ as starting materials. The particle size,crystal form,and crystal phase were determined with XRD and TEM. Average particle size of samples is about 15 nm.The catalytic effects of nanocomposite CuO·PbO on the thermal decomposition of RDX were investigated by DSC. The results show that the peak temperature of thermal decomposition shifts downward by 10.5 ℃,the decomposition enthalpy increases by 618 J·g^-1(about 55.7%),and the apparent activation energy of the thermal decomposition decreases by 46.05 kJ·mol^-1.