FIELD: chemical industry. SUBSTANCE: described is method of preparing hexanitrohexaaza isowurtzitane of formula VI: W(NO2)6 (VI) wherein w is hexavalent residue of hexaaza isowurtzitane of formula II: 
and NO2 is nitro group, by nitration of acyl-containing derivatives of hexaaza isowurtzitane, one of acyl-containing derivatives of hexaazaisowurtzitane is subjected to nitration, said hexaaza isowurtzitane being selected from group consisting of compound of formula I: WAn(NO2)(6-n) (1) wherein is integer of 4 or 5; A is identical or different and is C1-10 acyl group, and W and NO2 are as defined above; compound of formula III: WAn(NO)(6-n) (III) wherein W, A and n are as defined above, and NO is nitroso group; compound of formula IV: WAm(NO2)(6-m) (IV) wherein W and A are as defined above, and m is integer of 4-6, and H is hydrogen atom; with nitric acid in the presence of nitration accelerator, and at least one compound selected from group consisting of perfluoroalkylsulfonyl of formula IX: RfSO2NHSO2Rf′ (IX) wherein H is as defined above, and Rf and Rf′ are perfuloroalkyl groups containing 1-8 carbon atoms, S is sulfur atom, O is oxygen atom and N is nitrogen atom; phosphorus pentaoxide, sulfur trioxide, nitrogen pentaoxide and polyphosphoric acid, is useful as nitration accelerator. EFFECT: simplified process and high yield of the desired products. 31 cl, 65 ex
