Abstract: Cobalt and nitrogen co-doped biochar (Co/N-BC) was prepared from pine sawdust by impregnation and high-temperature calcination. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), Raman spectrometer (Raman), Fourier transform infrared spectrometer (FTIR) and automatic specific surface and porosity analyzer were used to analyze the morphology, composition and structure of the material. Co/N-BC catalyst was used to activate peroxymonosulfate (PMS) for the degradation of ciprofloxacin (CIP) in water. The results showed that the prepared Co/N-BC exhibited excellent performance in activating PMS to degrade CIP. The degradation efficiency of CIP reached 98.3% within 60 min, and remained 33.6% after 5 cycles. The free radical quenching experiments suggested that sulfate radical (SO₄ ^·–) played an important role in CIP degradation. The Co/N-BC material prepared in this study has broad application prospects in activating persulfate for the treatment of polluted wastewater.