1-Methyl-2, 4-dinitroimidazole(2, 4-MDNI) was synthesized via nitration, thermal rearrangement and methylation with imidazole as primary material. The single crystal of 1-methyl-2, 4-MDNI was cultivated in acetone and its crystal structure was determined by a four-circle X-ray diffractometer. The results indicate that the crystal is orthorhombic, space group P₂₁₂₁₂₁, with crystal parameters: a=6.215(12)Å, b=9.431(19)Å, c=23.531(5)Å, V=1379.3(5)ų, α=β=γ= 90°, D_c=1.658 g·cm^-3, Z=8, F(000)=704 and μ=0.149 mm^-1. The results reveal that 2, 4-MDNI has good thermal stability, and exhibits different thermodynamic behavior under different conditions.