Cu₂Cr₂O₅/SiO₂ was prepared by the improved coprecipitation method. The particles were characterized by scanning electron microscopy (SEM) and surface area analyzer (BET), and its catalytic effect on ammonium perchlorate was studied by differential thermal analysis (DTA). The results show that the particles is welldispersed, and larger specific surface area in comparison with pureCu₂Cr₂O₅, andCu₂Cr₂O₅/SiO₂composite particles make the temperature of the highertemperature exothermic peak of ammonium perchlorate decrease to 323.80 ℃. So the composite particles show good catalytic performance for the thermal decomposition of ammonium perchlorate. And test of the burning rate shows that the composite particles increase the propellant burning rate by 17%, and the relative activity of catalyst increases by 49%, and the pressure index declines.