The main factors affecting the drying process of TNT and their significance were investigated through a single factor test and a response surface method, from which the optimal drying conditions were determined. The results show that the moisture contents, vacuum, and temperatures are several important factors in controlling the drying process of TNT, and their significance is in the order of vacuum, temperature and moisture content. The optimum drying condition can be suggested as 0.03MPa for vacuum, 70℃ for temperature and 8% for moisture content.