In　this　study,　the　waste　sludge　was　modified　by　tannin　extract,　and　the　modified　material　Tannin　Extract-Sludge　Derived　Biochar　(TE-SDBC)　was　prepared　by　high-temperature　pyrolysis　at　700　degrees,while　tannin　extract　dosage　was　3.17　g,　pH　value　was　7.69.　TE-SDBC　was　used　to　activate　peroxydisulfate　(PDS)　for　the　degradation　of　tetracycline(TC).　The　sludge-based　biochar　was　characterized　by　ATR-FT-IR　spectroscopy,　BET,　SEM,　XRD,　XPS.　The　following　preparation　conditions　for　TE-SDBC　were　tannin　extract　dosage　was　3.17　g,　pH　value　was　7.69　and　pyrolysis　temperature　was　717.3　degrees　C.　TE-SDBC　had　more　defect　sites　and　higher　pyridinic　N　content,　which　was　conducive　to　promote　the　PDS　activation,　indicating　that　TE-SDBC　had　better　catalytic　performance.　The　TESDBC　obtained　optimal　conditions　were　as　follows:　the　initial　mass　concentration　of　TC　was　20　mg/L,　TESDBC　dosage　was　0.15　g/L,　PDS　dosage　was　0.1　g/L,　initial　pH　of　pollutant　solution　was　5.76　and　the　reaction　temperature　was　25　degrees　C.　The　degradation　of　TC　by　TE-SDBC/PDS　and　SDBC/PDS　was　explored.　After　120　min　reaction,　the　degradation　efficiency　of　TE-SDBC/PDS　was　40%　higher　than　that　of　SDBC/PDS,　and　the　optimization　of　the　conditions　indicated　that　the　TE-SDBC/PDS　system　had　a　better　removal　effect　on　TC　degradation.　Under　the　action　of　reactive　oxygen　species,　the　breakage　of　C=C　bond　happened,　the　functional　groups,　i.e.,　amino,　methyl　and　hydroxyl,　were　removed,　and　the　ring　opening　reaction　occurred　in　TC　molecule,　then　the　small　molecular　intermediates　were　ultimately　formed.　Finally,　the　intermediate　products　were　mineralized　into　CO2,　H2O　and　various　inorganic　substances.