In this work, a new series of monocyclic compounds based on 1,2,4-oxadiazol-5(4H)-one was synthesized. The molecular structure, thermal stability and sensitivity to external stimuli for these compounds were characterized by X-ray diffraction analysis, NMR (1H and 13C) spectroscopy, IR spectroscopy, differential scanning calorimetry (DSC) and the standard BAM method. Compound 3-((2,2,2-trinitroethyl) amino)-1,2,4-oxadiazol (3) with trinitromethyl exhibits a higher decomposition temperature (Td = 143°C) than that of 3-(dinitromethyl)-1,2,4-oxadiazol-5-one (4) (Td = 76°C) reported in the literature. In addition, compound 3 exhibits lower impact sensitivities (IS) (IS = 10 J) than 4, N3-(2,2,2-Trinitroethyl)-1,2,4-oxadiazole-3,5-diamine (5) and RDX (4: 6 J; 5: 6 J; RDX: 7.4 J). Charge distribution and Hirshfeld surface were calculated to make further research on the intermolecular interaction of 3 with trinitromethyl. The difference in stability of these compounds is mainly due to the existence of intermolecular hydrogen bonds. These results indicate that compound 3 has promising application prospects as the energetic material.