2, 2, 4, 4-Tetranitroadamantane was synthesized via Baeyer-Villiger oxidation, lactone rearrangement, ketalization, oxidation and gem-nitration etc unit reaction using adamantan-2-one as raw material. The synthesis condition of an important intermediate 4, 4-(ethylenedioxy)adamantan-2-one was optimized. The gem-nitration reaction of 4, 4-(ethylenedioxy)adamantan-2-one oxime was performed using green nitration agent dinitrogen pentoxide (N₂O₅). The effects of solvent, temperature, reaction time and ratio of material on the first-step gem-nitration reaction were investigated. Results show that the optimum reaction conditions of the reaction are determined as: methylene chloride as solvent, the molar ratio of 4, 4-(ethylenedioxy)adamantan-2-one oxime to N₂O₅ is 1:3, reaction temperature 45 ℃ and reaction time 30 min with yield of 52.3%. The overall yield of 2, 2, 4, 4-tetranitroadamantane is 14.2%, which is 1.9 times higher than that reported in reference.