A new energetic salt of 2, 4-dinitroimidazole ([(DNI)NH₂ (CH₃)₂]) was synthesized with yield of 62.7% by using 2, 4-dinitroimidazole as starting materials. The structure of [(DNI)NH₂ (CH₃)₂] was characterized by IR, elemental analysis, fourcircle single crystal X-ray diffraction NMR. Results show that the crystal of title compound belongs to monoclinic system, space group C2/c with a=31.403(5)Å, b=6.7133(7)Å, c=22.769(4)Å, α= 90.00°, β =126.80(3)°, γ=90.00°, V=3843.6(10)ų, Z=16, D_c=1.404 g ·cm^-3, F(000) = 1696.0, μ (MoK_α) = 0.121 mm^-1. The molecule packing of [(DNI)NH₂ (CH₃)₂] is not compacted. Intra molecular and intermolecular hydrogen bonds are weak and the density is lower. Thermal properties were tested by TG-DSC. Results reveal that the [(DNI)NH₂ (CH₃)₂] shows good thermal stability.