The synthesis of 3,6-diguandine-1,2,4,5-tetrazine(BDT) and its salts were described from triaminoguanidine nitrate and 2,4-pentanedione after condensation, oxidation and neutralization. Their structures were confirmed by IR, HMR, DSC. Taking CH₃COOH-NaNO₂ as oxidizer, CH₃COOH as reactive medium, BDT was obtained with the yield of 85% at room temperature . This improvement reduces the cost of synthesis, raises the yield, facilitates experimental operation.