Recently, a new type of high-energy explosive (TNTNB) has been synthesized. Before fully understanding its detonation performance and safety features, it is necessary to conduct certain studies on its basic physical properties. For this purpose, we have employed first-principles methods to investigate the structural, electronic, vibrational, and thermal properties of TNTNB. The optimized lattice parameters of TNTNB crystals differ from the experimental values by less than 2 %. The electronic properties calculation results show that TNTNB has an indirect bandgap of 2.1508 eV. The phonon dispersion and density of phonon states indicate that its phonon bath modes region is 0–245 cm−1, and the doorway modes region is 245–735 cm−1. Additionally, the calculated energy transfer rate is 3.460 × 1012 J/K/mol, and the phonon-vibration coupling coefficient is 3.31. The zero-point energy calculated from the density of phonon states is 1669.06 kJ/mol, and the isochoric heat capacity at 300 K is 1441.48 J/K/mol.