The Cu/CNTs composite particles were prepared by the chemistry sediment method and using the carbon nanotubes as the carrier. The composite particles obtained were characterized by SEM, TEM. To analyze the catalytic effect of Cu/CNTs composite particles on the thermal decomposition of AP in the composite particles , the comparison sample by simply mixing Cu particles and CNTs particles with AP respectively was prepared and DTA experiments were used to characterize their catalytic performance . Results indicate that the catalytic performance of Cu/CNTs composite particles is superior to that of the simply mixed sample. Compared with the simply mixed sample of Cu and CNTs and AP, the peak temperature of high temperature decomposition of Cu/CNTs composite particles decreases 11.4℃, and the total heat release improves from 494.06J/g to 711.13J/g. It is shown that the catalytic performance of Cu and CNTs on the thermal decomposition of AP can be improved by composition.