10g of lutetium (III) oxide is added to the 500mL 50% acetic acid aqueous solution, and heated in a steam bath to dissolve. Sometimes lutetium (III) oxide needs to be heated in a steam bath for a week to completely dissolve. If a small amount of lutetium (III) oxide still fails to dissolve after heating for a week, it needs to be filtered. Heat the clear solution on a 75°C water bath to evaporate most of the solvent. Cooling, the crystals are precipitated, the crystals are filtered, moved into a glass dish, and dried in a vacuum dry holder with granular sodium hydroxide and magnesium perchlorate. The product obtained is hydrate. Place the hydrate crystals in a vacuum drying gun (Abd Hatton dryer) and dry them under reduced pressure (vacuum) at 75°C to constant weight to obtain anhydrous lutetium acetate (III).