FOX-7 is a typical high-energy and low-sensitivity material. Due to the unique “push-pull” nitroenamine structure, abundant derivatives with good performance can be synthesized. DFT method is used to study the synthesis mechanism for two FOX-7 amino-substituted derivatives. The synthesis mechanism of amino-substituted derivative MTNzA is cyclization followed by isomerization, which is different from the pathway of isomerization followed by cyclization proposed by previous authors. Carbohydrazide is tend reacted with two FOX-7 to produce BADCh, rather than ring formation with one FOX-7.