Abstract:With acetylacetone and hydrazine hydrate as primary substances, 1H,4H-3,6-dinitropyrazolo[4,3-C] pyrazole(DNPP) was synthesized by the process of dehydration and condensation,the first nitration,reduction,diazotisation,intramolecular cyclic condensation,the second nitration,oxidation,decarboxylation and nitration in turn. The overall yield of DNPP was 9.3%. Its structure was confirmed by IR,1H NMR, 13C NMR and elemental analysis. The mechanism of intramolecular cyclization reaction was presented. The results provide academic and experimental basis for the further research on the pyrazolo[4,3-C]pyrazole explosives.