The challenge of achieving fast and efficient separation of photogenerated carriers lies in the kinetics of photocatalytic reactions. In the present study, we employed solvothermal and surfactant-induced methods to uniformly grow BiOCl on the surface of CoS Nano-flower balls, thereby forming core-shell Schottky heterojunctions. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations demonstrated the directional transfer of electrons and the establishment of an enhanced built-in electric field during the formation of these heterojunctions. This rapid separation of photogenerated carriers effectively activates the photo-Fenton system and enhances its synergistic effect. After 60 min of light exposure and the addition of Peroxymonosulfate (PMS), 100C-PBOC effectively degraded 95.6 % of ciprofloxacin, exhibiting a degradation rate k-value that is 1.97 times higher than that of photocatalytic degradation alone. Considering the insufficiency of mineralization, we conducted liquid chromatography-mass spectrometry (LC-MS) tests in conjunction with DFT calculations to elucidate the complete degradation mechanism and assess the toxicity of the degraded intermediates, most of which exhibited significantly reduced toxicity. This study addresses the gap in the application of CoS co-catalysts in photocatalytic wastewater treatment and offers a novel approach to the design of core-shell heterojunctions.