Fused-ring energetic compounds， composed of two or more rings sharing two atoms and one chemical bond， have sizeable π-π conjugate structures and are a kind of popular new energetic materials. The polycyclic coplanar structure of energetic fused rings shows good molecular stability. Furthermore， the coplanar structure is featured with high heat of formation， significant ring tension， and high energetic performance. It can achieve a balance between high performance and molecular stability. With a C—N bond as the common building block， these nitrogen heterocycles have good density， stability， and numerous modifiable sites， which have become a new class of backbones in the field of energetic fused heterocycles. In this paper， the authors review the recent advance of synthesis， detonation properties， stability， and outlook of C—N type fused-ring energetic materials， which will be useful for the energetic community in future studies.