The 2, 6-diamino-3, 5-di-nitropyrazine-1-oxide (LLM-105) crystals with three different morphology were recrystallized using two ionic liquids of [Bmim]BF₄ and [Bmim]CF₃SO₃ as solvents under different solvent temperature, water volume and standing conditions. The morphology, crystal structure, thermal property and purity of the crystals were characterized by scanning electron microscope, X-Ray powder diffraction, differential scanning calorimetry-thermogravimetry, fourier transform infrared spectroscopy and purity analysis. Results show that the recrystallized rectangular micro-rod, hole shape and plate-like LLM-105 crystals have the same diffraction peak positions as the raw materials, only the intensity have obviously enhanced at 11°, 21°, 45° and weakened at other positions. Compared with the raw materials, the crystals habits have changed and present different facets, while the purity have slightly improved (above 94%). The relative regular structured rectangular micro-rod crystal exhibits the best thermal stability with the exothermic peak temperature of 353 ℃ and initial decomposition temperature of 323.6 ℃ which have improved by 10 ℃ and 40 ℃ than that of the raw materials, respectively.