Two types of 15N substituted ammonium nitrate, namely 15NH4NO3 and NH415NO3, were prepared by using isotope substitution technique to replace 14N in ammonium nitrate(NH4NO3)with 15N. The apparent morphology and chemical structure of 15N substituted ammonium nitrate were investigated using scanning electron microscopy, infrared spectroscopy, and X-ray diffraction. Its density, decomposition temperature, hygroscopicity, sensitivity, detonation velocity, and heat of explosion were tested by true density analyzer, differential scanning calorimeter, desiccator equilibrium method, and micro-charge laser ignition technique. The results show that, compared with common ammonium nitrate, the chemical structure of 15N substituted ammonium nitrate is almost unchanged. The density of NH415NO3 and 15NH4NO3 increases from 1.72g/cm³ to 1.75g/cm³ and 1.76g/cm³, the hygroscopic speed decreases to 97.1% and 95.2%, respectively. And the sensitivity and thermal stability are almost the same. The detonation performance tested by a self-built micro-charge laser ignition device show that the detonation velocity of NH415NO3 and 15NH4NO3 increases to 6610m/s and 6680m/s, and the heat of explosion increases to 3730kJ/kg and 3840kJ/kg, respectively, proving that stable isotope substitution technology can be an alternative to further enhance the performance of existing high-energy materials.