Nanometer α-Fe_2O_3 catalysts were prepared by hydrolyzation in high temperature. Three kinds of precipitators, NaOH, (NH_4)_2CO_3 and urea were used to compare the effect in the process of hydrolyzation. Nanometer sizer, transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to test the profiles and diameters of the product particles. The test results indicate that the production is nanometer α-Fe_2O_3 with narrow particle size distribution (PSD) and good dispersibility. The catalysts are mixed with ammonia perchlorate (AP) in 1.0 wt.%. And the composite particles of catalysts with AP are prepared using a new solvent-nonsolvent method. Differential thermal analyzer (DTA) is employed to analysis the thermal decomposition of the composite particles and pure AP sample. The results imply that the thermal decomposition curve peaks of the samples in which nanometer α-Fe_2O_3 catalysts are added appear comparatively more ahead than that of pure AP sample. Among these mixtures added nanometer material, the smaller the particle diameter of catalyst is, the more ahead the thermal decomposition curve peaks of AP appear. The high and low temperature thermal decomposition curve peaks of AP mixed with the catalyst deposed by urea are more ahead of 77.8?℃ and 9.7?℃ than that of pure AP, respectively. The mechanism of the catalyst deposed by urea with smaller diameter and the distinct catalysis of the particles on the thermal decomposition of AP are discussed. Nanometer α-Fe_2O_3 catalysts were prepared by hydrolyzation in high temperature. Three kinds of precipitators, NaOH, (NH_4) _2CO_3 and urea were used to compare the effect in the process of hydrolysis. Nanometer sizer, transmission electron microscopy (TEM) and X- ray diffraction (XRD) were employed to test the profiles and diameters of the product particles. The test results indicate that the production is nanometer α-Fe_2O_3 with narrow particle size distribution (PSD) and good dispersibility. The catalysts are mixed with ammonia perchlorate AP) in 1.0 wt.%. And the composite particles of catalysts with AP are prepared using a new solvent-nonsolvent method. Differential thermal analyzer (DTA) is employed to analyze the thermal decomposition of the composite particles and pure AP sample. The results imply that the thermal decomposition curve peaks of the samples in which nanometer α-Fe_2O_3 catalysts are added appear comparatively more ahead than that of pure AP sample. Among t the smaller the particle diameter of catalyst is, the smaller the particle diameter of catalyst is, the smaller the particle diameter of catalyst is, the more the thermal decomposition curve peaks of AP appear. The high and low temperature thermal decomposition curve peaks of AP mixed with the catalyst deposed by urea are more ahead of 77.8 ? C and 9.7? C than that of pure AP, respectively. The mechanism of the catalyst deposed by urea with smaller diameter and the distinct catalysis of the particles on the thermal decomposition of AP are discussed.