A preparation method of 1-amino-1,2,3-triazole was developed.The glyoxal bishydrazone was synthesized from glyoxal and aqueous hydrazine,and then glyoxal bishydrazone was oxidated with activated manganese dioxide to give 1-amino-1,2,3-triazole.The structure of 1-amino-1,2,3-triazole was confirmed by IR,elemental analysis,NMR and MS.Results show that 1-amino-1,2,3-triazole with high purity(96%)can be optimally got by crystallization from acetonitrile.The optimal amount of manganese dioxide is 2.8 N to the amount of glyoxal bishydrazone,and the reaction can be achieved within 2.5 h with the yield of 78.30%.In addition,the reaction mechanisms of decomposition and synthesis of 1-amino-1,2,3-triazole were discussed.