Sulfate　radical-based　advanced　oxidation　processes　exhibit　great　potential　for　the　degradation　of　organic　pollutants.　In　this　study,　P-doped　biochar　(PBC500)　was　successfully　synthesized　by　the　pyrolysis　of　H3PO4-impregnated　cow　manure　waste　and　was　employed　to　activate　peroxymonosulfate　(PMS)　for　the　elimination　of　17　beta-estradiol　(E2).　The　characterization　results　showed　that　the　surface　area,　defective　structure,　and　functional　groups　(C=O　and　phosphorus-containing　groups)　of　biochar　increased　after　H3PO4　modification.　PBC500　exhibited　high　PMS　activation　activity　and　excellent　E2　degradation　capacity;　97.91%　of　3　mg/L　E2　can　be　removed　within　90　min　using　0.2　g/L　PBC500　and　1　mM　PMS.　Based　on　the　quenching　experiments　and　X-ray　photoelectron　spectroscopy　(XPS)　analysis,　defective　structures,　C=O,　and　P-C　groups　on　biochar　act　as　active　sites　to　promote　the　catalytic　oxidation　of　E2　by　generating　O2-　and　1O2.　In　addition,　PBC500　displayed　excellent　reusability,　achieving　65.15%　E2　degradation　after　three　reuse　cycles.　Overall,　this　study　presented　a　new　technique　that　supports　a　high　efficiency,　environmentally　friendly,　and　low　cost　treatment　method　for　E2　wastewater　and　simultaneously　provided　a　new　option　for　the　resource　utilization　of　livestock　waste.