Density functional theory and volume-based thermodynamics calculations have been performed to study the crystal densities, heats of formation (HOFs), energetic properties, thermodynamics of formation, and impact sensitivity for the salts composed of heterocycle-functionalized nitraminofurazanate-based anions and triaminoguanidinium cation. The results show that the triaminoguanidinium nitraminofurazanate-based salts have high densities and positive HOFs. The substitution of the oxygen-containing substituent (-NO2 or -C(NO2)(3)) is helpful for enhancing the densities and detonation properties of the nitraminofurazanate-based salts, and the substitution of -C(NO2)(3) exhibits the best performance. Incorporating the conjugated bridge -N=N or -N=N-N=N- into the heterocycle-functionalized nitraminofurazanate-based salts is favorable for improving the density and detonation properties of its salt. The tetrazole-functionalized salts exhibit the best detonation properties among the three salt series. The calculated h(50) values suggest that the introduction of the bridge -NH- or -NH- NH- decreases the sensitivities of the heterocycle-functionalized nitraminofurazanate-based salts.