The search for coplanar high‐energy insensitive explosives is a new direction in the research of energetic materials. A series of coplanar compounds based on the [1,2,4]triazolo[4,3‐b][1,2,4]triazine skeleton (ATTZ) were designed and studied using density functional theory. The research content includes density, detonation performance, shock sensitivity, bond‐dissociation energy, thermodynamic properties, and electrostatic potential. The formation of intramolecular hydrogen bonds between the energetic groups connected by these coplanar compounds and the introduction of coordinated oxygen on the parent to improve detonation performance are the highlights of this study. The results show that most of the compounds have good density, low sensitivity, and excellent detonation performance. And compound A11 shows a high density (d = 1.93 g/cm3), detonation velocity (D = 9.12 km/s1), and explosion pressure (P = 38.41 GPa), with the bond dissociation energy value of 253.4 kJ/mol. Designing coplanar compounds is an efficient approach to explore high‐energy insensitive explosives.