In order to establish a safe, effective and green method, the reduced-sensitivity HMX was prepared by recrystallization from ionic liquid-solvent system with solvent-nonsolvent technique, using a series of ionic liquids [mimH]NO₃, [mimBSO₃H]NO₃, [Et₃NH]NO₃ and [Et₃NBSO₃H]NO₃ as crystal assistants, acetone and cyclohexanone as solvent. Results show that the reduced-sensitivity HMX with spherical crystal can be recrystallized at 60 ℃ at the stirring rate of 750 r·min^-1 in the presence of ionic liquid [mimBSO₃H]NO₃ (1.5% weight of HMX) using cyclohexanone as solvent. The obtained HMX is smooth surface and neat edge with thermal decomposition peak temperature of 288 ℃, and impact sensitivity of 4%.