Nano-TiO₂ powder was prepared at different treatment temperatures by sol-gel method. The effects of nano-TiO₂/UV photocatalytic degradation reaction on TNT and HMX were explored at different reaction temperatures and different intensities of light source. The results show that the degraded effects of the nano-TiO₂/UV system are more excellent than that of only UV reaction system, the degraded ratios for TNT and HMX can be up to 93.46% and 94.12% respectively. The catalysis activity of TiO₂ is affected by granularity, and the degraded capability of anatase TiO₂ calcined from 490 ℃ is better than that at other treatment temperatures. It is good to improve the degraded ratios at higher reaction temperatures and stronger intensities of UV light source. The kinetic reaction mechanisms of the photocatalytic degradations conforms to the Langmuir-Hinshelwood Model and the reaction rate for HMX is faster than that for TNT.