Nitroimidazole heterocyclic compound 2, 4-dinitroimidazole (2, 4-DNI) has been synthesized. Its molecular structure was characterized by IR, MS, 1H-NMR, 13CNMR and elemental analysis. The experimental thermal stability, sensitivity and security of 2,4-DNI show that 2,4-DNI is well thermal stable, better than RDX and other nitramine explosives, has low mechanical sensitivity approaching to TATB or TNT and good electrostatic sensitivity. So, it will be one insensitive or low sensitivity high explosive has promising applications in many insensitive ammunitions in future.