Catalytic activity of nanocrystalline transition metal oxides on the decomposition of energetic material NH4ClO4 (AP) is investigated by thermal analysis. Results indicated that the nanocrystalline CuO powders have most strongly catalytic activities comparing with other mono-metal oxides. Moreover, the catalytic activities of the nanocrystalline CuO powders on the decomposition of AP have relationship with preparing methods and the microstructure of nanocrystalline CuO powders. Among them, the catalysis of the spherical shape nanocrystal CuO powders with better dispersion on AP decomposition is the strongest, and it can made the higher temperature peak of AP decomposition drop down 93.19 ℃ and made thermal power rise to 1 420 J·g^-1 by 590.12 J·g^-1. Nanocrystalline Fe₂O₃ with doping with Cu²⁺(5%) can greatly enhance its catalytic activity on the decomposition of AP, and it made the higher temperature peak of AP decomposition drop down 78 ℃ by 35 ℃ (continuing dropping 43 ℃), and made thermal power rise to 1 230 J·g^-1by 980.50 J·g^-1. Compared with mono-metal oxides, some new multi-metal oxides have more strongly catalytic activities. Especially compound 1, it made the higher temperature peak of AP decomposition drop down more 110℃ and made thermal power rise to 1 470 J·g^-1.