Abstract:4,5-Bis(1H-tetrazol-5-yl)-1H-imidazole(H3BTI) is a high-nitrogen azole compound which may be suitable as ingredient for low signal propellant and gas generator. The synthetic technology of H3BTI was optimized with the yield of 94.6% as following: the molar ratio of 4,5-dicyanoimidazole, sodium azide and ammonium chloride, 2.2:2.2:1, solvent DMF, reaction temperature 90 ℃, and reaction time 8 h. The thermal behavior and non-isothermal decomposition kinetics of H3BTI were studied with DSC and TG/DTG method. Results show that the kinetic parameters of thermal decomposition reaction, are the activation energy and pre-exponential factor are 197.62 kJ·mol-1 and 16.16, respectively, and the critical temperature of thermal explosion of H3BTI is 556.38 K, which indicates that H3BTI has better thermal stability than that of RDX, and activation entropy, activation enthalpy and activation Gibbs free energy of the thermal decomposition are 35.72 J·mol-1·K-1, 193.66 kJ·mol-1 and 173.33 kJ·mol-1, respectively.