Abstact: 5-amino-3-mercapto-1,2,4-triazole (AMZ) is an important intermediate in organic synthesis. It has widespread usage in the fields of pesticide, medicine, imaging materials and so on. Based on the consultation of a large number of literature and the comparison of the advantages and disadvantages of various methods about the synthesis of 5-amino-3-mercapto-1,2,4-triazole (AMZ), the best route is: take aminoguanidine bicarbonate and ammonium thiocyanate as raw materials to synthesize the product. And based on the experimental explorations of the amount of adducts, reaction solvent volume, and reaction temperature, the optimum conditions of this route are: the ratio of the amount between aminoguanidine salt and ammonium thiocyanate is 1:1.2; the ratio of the amount between aminoguanidine salt and sodium hydroxide is 1:1.3; the temperature of hydrochloride is 98 ° C; the temperature of sodium hydroxide is 110 ° C; In optimum conditions, the yield of AMZ is 83.90%.