The aim of this work is to investigate the effect of potassium permanganate (KMnO₄) on the photocatalytic degradation of hexafluorobisphenol A (BPAF) by peroxymonosulfate (PMS). The influences of the experimental conditions such as PMS and permanganate dosage, solution pH were analyzed. Furthermore, the process for the oxidative removal of BPAF in natural water was confirmed and its efficiency compared with that of UV/PMS process. Results showed that KMnO₄ had a positive effect on the BPAF degradation in the UV/PMS process. The degradation efficiency was increased with the increase of PMS dosage. With the dosage of KMnO₄ increased from 0 to 1.5 μmol/L, the optimum removal efficiency of BPA obtained when PMS was 1 mmol/L. Further addition of KMnO₄, however, had no significant promotion on the extent of BPAF oxidation efficiency. BPAF degradation rate inhibited with increasing the pH under acidic condition, while promoted significantly under alkaline condition. The BPAF removal percentage in UV/PMS/KMnO₄ was about 12%-14% higher than in UV/PMS system in actual water. The mechanism of the synergetic combination of PMS with KMnO₄ for BPA degradation under the UV irradiation indicated that the catalytic oxidation of some reactive manganese intermediates generated in the UV/PMS/Mn(Ⅶ) process.