Modified　magnetic　chitosan　nanoparticles　(EMMCS-G),　used　as　a　Fenton-like　catalyst,　were　successfully　prepared　and　modified　with　glutaraldehyde　and　ethylenediamine.　EMMCS-G　has　strong　magnetization,　good　reusability,　stability,　environmental　friendliness,　and　high　efficiency.　In　the　Fenton-like　system,　the　synergistic　effect　of　adsorption　and　advanced　oxidation　significantly　enhances　the　removal　effect　of　tetracycline　(TC).　The　optimal　concentration　of　persulfate　was　found　to　be　20　mmol　L-1,　and　at　a　pH　of　3,　the　removal　efficiency　of　TC　reached　95.6%　after　6　hours.　The　oxidation　system　demonstrated　excellent　pH　adaptability,　achieving　a　TC　removal　rate　of　94%　within　6　hours　across　a　pH　range　of　3　to　8.　Hydroxyl　((OH)-O-center　dot)　and　sulfate　(SO4-(center　dot)　)　radicals　were　present　in　the　reaction　system,　with　(OH)-O-center　dot　playing　an　important　role　in　the　oxidation　process　of　TC.　The　attack　sites　of　tetracycline　were　identified　using　density　functional　theory　(DFT),　and　five　degradation　pathways　for　TC　were　proposed　based　on　LS-MS　experiments.　Finally,　quantitative　structure-activity　relationship　(QSAR)　analysis　was　employed　to　assess　the　toxicity　of　the　intermediates.　Overall,　toxicity　gradually　decreased,　indicating　that　the　Fenton　reaction　system　effectively　reduced　the　toxicity　and　mutagenicity　of　TC.　This　study　suggests　EMMCS-G　as　a　potential　catalyst　for　enhanced　Fenton-like　degradation　with　excellent　efficiency　observed　for　the　degradation　of　tetracycline　for　environmental　remediation.