The work aims to prepare TiO2/CNTs composite particles and study their catalytic performance on the thermal decomposition of ammonium perchlorate. The Ti-sol was prepared at ambient temperature with the tetrabutyl orthotitanate and acetylacetone as titanium source and stabilizer respectively. Then, the TiO2/CNTs composite particles were prepared by sol-reflux method at 80℃ under normal pressure with modified carbon nanotubes as carrier. The crystals of composite particles were determined by XRD, the surface morphology was observed by TEM and the surface functional group and element composition were characterized by FT-IR and XPS. The catalytic performance of the TiO2/CNTs on the thermal decomposition of AP was investigated by TG-DSC analysis. From the results, the hydroxyl and carboxyl functional groups were abound on the surface of carbon nanotubes after modified with concentrated acid. TiO2 nanoparticles were attached on carbon nanotubes with thickness of 2~4 nm. Crystal forms of TiO2 in composite particles were mixed with anatase and rutile. TiO2/CNTs nanoparticles had significant catalyst performance on the thermal deposition of AP and could remarkably decrease the peak temperature of high temperature decomposition of AP by 52.5 ℃. Then, the exothermic peak changes from endothermic peak and the low temperature decomposition peak almost disappeared. TiO2/CNTs nanoparticles can promote the thermal decomposition of AP and have better catalytic performance than that of TiO2, CNTs and their mixture.