In order to study the reaction mechanism of nitration/nitrolysis of tetraacetylhexaazaisowurtzitane(TAIW) with the mixture of nitric acid and sulfuric acid,all of the intermediates,tetraacetyldinitrohexaazaisowurtzitane,triacetyltrinitrohexaazaisowurtzitane,two isomers of diacetyltetranitrohexaazaisowurtzitane and monoacetylpentanitrohexaazaisowurtzitane were separated by means of quenching the reaction mixture at proper time and characterized by element analysis,NMR,FTIR,MS and X-ray diffraction. The results show that the two free secondary amines of TAIW are nitrated firstly and then the four acetyl groups of TAIW are nitrolysed one after one under conditions of elevating the reaction temperature. Moreover,all of the intermediates stated above of the nitration processeses were detected by thin layer chromatography(TLC) techniques.