Abstract: To separate molybdenum-99 from fission products of low enriched uranium (LEU) by precipitation with α-benzoin oxime (α-BO), influences of temperature, concentration of nitrate, molar ratio of α-BO to Mo, radiation dose and uranium concentration on precipitating molybdenum with α-BO had been evaluated. Re-dissolution of MoO₂(α-BO)₂ was performed. The decontamination factors of impurity elements including strontium、 zirconium、 ruthenium、 cesium、 cerium、 iodine-131 and uranium had been determined. The recovery yield of Mo for the separation procedure was calculated. It showed that, at the room temperature, with 1 mol/L of nitric acid concentration, higher than 2 of molar ratio of α-BO to Mo, when α-BO was dissolved in anhydrous ethanol or 0.4 mol/L sodium hydroxide solution, higher than 95% of Mo recovery yield could be obtained. Under the radiation dose rate of 5 000 Gy/h, when the radiation dose increased, Mo recovery yield decreased instead. When the total radiation dose of α-BO was below 8.25×10⁵ Gy, Mo recovery yield was higher than 85%.When uranium concentration increased, Mo recovery yield decreased. MoO₂(α-BO)₂ precipitate could be dissolved in sodium hydroxide of 0.5 mol/L within 15 minutes. Effective decontamination for all major impurity elements including strontium, zirconium, ruthenium, cesium,cerium, iodine and uranium were observed. This study has paved the pay for further research for fission ⁹⁹Mo production.