The oxidation of oxygen ions and the generation of an anode effect at a low oxygen content of 150 mg/kg were discussed in this pa-per. Cyclic voltammetry and square-wave voltammetry tests were conducted to explore the anodic processes of LiF-NdF3 melt after a lengthy period of pre-electrolysis purification at 1000℃ (during which the oxygen content reduced from 413 to 150 mg/kg). The oxidation process of oxygen ions was found to have two stages: oxidation product adsorption and CO/CO2 gas evolution. The adsorption stage was controlled by diffusion, whereas the gas evolution was controlled by the electrochemical reaction. In comparison with oxygen content of 413 mg/kg, the de-crease in the amplitude of the current at low oxygen content of 150 mg/kg was much gentler during the forward scanning process when the an-ode effect occurred. Fluorine-ion oxidation peaks that occurred at about 4.2 V vs. Li/Li+ could be clearly observed in the reverse scanning pro-cesses, in which fluorine ions were oxidized and perfluorocarbons were produced, which resulted in an anode effect.