A new class of high‐energy density covalent organic framework has been predicted on the basis of the extensive quantum chemistry computational studies. Two state‐of‐the‐art energetic materials with the chemical formula C10H8N8 are generated by the inter‐tiling condensation starting from the divergent tertra‐substituted methane and the ditopic glyoxal or hydrazine. Both energetic covalent organic frameworks (eCOFs) involve the 3D interpenetrated diamond nets with the cage vertices connected by either CC or NN bonds. The densities of eCOFs increase to 2.6 g/cm3. Ab initio molecular dynamics simulations prove that eCOF‐300a and eCOF‐300b are thermally stable up to 1200 and 800 K, respectively. The enthalpy of formation was predicted to be 241.8 and 315.0 kcal/mol for eCOF‐300a and eCOF‐300b, respectively. This work provides a great opportunity to extend the applications of COFs to develop new energetic materials with predictable properties and energetic performance superior to CL‐20.