N self-doped porous biochars (KBCs) were synthesized through high-temperature carbonization and KHCO3 activation using chicken feathers as biomass. Subsequently, it was employed for the remediation of tetracycline hydrochloride (TC)-contaminated water and soil. The properties of KBCs were analyzed by various characterization techniques. The results verified that KBC800-2 exhibited outstanding specific surface area (1648.89 m(2) g(-1)) and pore volume (0.806 cm(3) g(-1)). The maximum adsorption capacity of KBC800-2 for TC was 147.8 mg g(-1), which was superior to that of raw biochar (15.5 mg g(-1)). The results of pseudo-second-order and Freundlich indicated that the process was dominated by chemisorption. Moreover, the adsorption capacity of KBC800-2 was stable over a wide pH range of 3-12 and high coexisting ionic strength. The consequences proved that the enhancement of pore filling effect and pi-pi electron interactions between TC and N self-doped adsorbent were the predominant driving forces to improve the adsorption efficiency of TC. Notably, compared to T50 (soil and 50 mg kg(-1) TC), the properties of organic carbon, total nitrogen, and sucrase, urease, and catalase activities in TKBC800-2 (soil, 50 mg kg(-1) TC, and 2% KBC800-2) were increased by 108.57%, 4.98%, 886.08%, 89.52%, and 78.08% respectively. KBC800-2 as a low-cost and highly effective adsorbent for antibiotic pollution has enormous application potential.