In the early stage, studies on pentazole chemistry are mainly focused on the substituent effect and stability of aryl pentazole compounds, but the successful preparation of room-temperature stable pentazole ionic compounds has not been achieved. Until to 2017, for the first time, the Chinese scientists reported their successful preparation of isolated and stable cyclo-N₅^- compounds through an oxidative cleavage strategy at low temperature. Subsequently, a variety of cyclo-N₅^- based salts with different structures were synthesized, attracting a wide of attention in the fields of energetic materials. Up to now, full-nitrogen pentazole materials have achieved a series of breakthroughs and various full-nitrogen pentazole salts have also been prepared with the de composition temperatures mostly higher than 100 ℃. The ionic salts based on cyclo-N₅^- anion and nitrogen-rich cations will open a new avenue to develop cyclo-N₅^- based energetic materials. This work reviews the theoretical calculations, organic syntheses, structural characterization, and the perspectives on pentazole compounds, which aims to provide guidance for the researchers working in the field of polynitrogen materials.