The hydrolysis and nitration reaction of tetraacetylhexaazaisowurzitane (TAIW) were studied under several nitration conditions. By using the catalyst, nitration of TAIW in the system of dilute nitric acid can give hexanitrohexaazaisowurtzitane (HNIW) with yield of over 95% and purity over 99%. Moreover,a new method was found out to synthesize HNIW.