The synthesis of two fused high-nitrogen compounds and their energetic salts is presented. All new compounds were well characterized by IR and multinuclear NMR spectroscopy, thermal analysis, and elemental analysis. Some of them (5-8, and 11) were further determined by single crystal X-ray diffraction analysis. With high nitrogen contents (59.6-76.8%) and tremendous ring-strain energy, these fused compounds exhibit high positive heats of formation ranging from 2.35 to 4.23 kJ g-1, much higher than those of RDX (0.32 kJ g-1) and HMX (0.25 kJ g-1). The high enthalpies and extensive noncovalent interactions (hydrogen bonds and π-π interaction) impart them with promising detonation performance. Their energetic performance was evaluated using EXPLO5. Among them, compounds 7, 10, and 11 exhibit high densities, good detonation properties, and excellent mechanical stabilities, thereby highlighting their potential applications as new insensitive energetic materials.