In order to improve the safety of the high explosive 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW), we cocrystallized HNIW with the insensitive explosive DNB (1,3-dinitrobenzene) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that it belongs to the orthorhombic system with space group Pbca. Therein, layers of DNB alternate with bilayers of HNIW. Analysis of interactions in the cocrystal indicated that the cocrystal is mainly formed by hydrogen bonds and nitro-aromatic interactions. Moreover, the thermal behavior, sensitivity, and detonation properties of the cocrystal were evaluated. The results implied that the melting point of the cocrystal is 136.6 degrees C, which means an increase of 45 degrees C relative that of pure DNB. The predicted detonation velocity and detonation pressure of the cocrystal are 8434 m s(-1) and 34 GPa, respectively, which are similar to that of the reported HNIW/TNT cocrystal, but its reduced sensitivity (H-50 = 55 cm) makes it an attractive ingredient in HNIW propellant formulations.