N-heterocyclic compounds, as typical multi-nitrogen compounds, had currently attracted significant attention in the filed of new energetic materials. Introduction of azo bond into nitrogen-containing heterocyclic compounds was a feasible approach to increase their energy and density. Methods of introducing the azo bond into nitrogen-containing heterocyclic compounds via oxidation-coupling reaction of hydrazo-azo and amino-azo were reviewed. The effects of different oxidants on oxidation-coupling reaction were discussed. Increasing the reactivity and selectivity of oxidants is a main development direction for oxidation-coupling reaction of N—NH₂ in nitrogen-containing heterocyclic compounds. 42 references were included.