The invention discloses an antibacterial wear-resistant cotton yarn, which is prepared from cotton, antibacterial master batch, viscose, liquid epoxy resin, diethanolamine, castor oil, nano tourmalinepowder, far infrared ceramic powder, nano titanium dioxide, polyethylene wax, polyethylene glycol and a hydrophobic agent. The preparation method comprises the steps: (1) mixing corresponding parts by mass of cotton, viscose and antibacterial master batch, and hardening the mixture; (2) carding to obtain cotton fiber slivers; (3) mixing castor oil, nano tourmaline powder, far infrared ceramic powder and nano titanium dioxide to prepare a mixed emulsion; (4) soaking the cotton fiber slivers in the mixed emulsion to obtain expanded cotton fiber slivers; (5) taking a hydrophobic agent, soaking the dried cotton fiber slivers into the hydrophobic agent, oscillating and dispersing; and (6) drying the treated cotton fiber slivers, carding, combing, and drawing to obtain the cotton yarn. The antibacterial wear-resistant cotton yarn has bacteriostasis and sterilization effects, and has good wear resistance and therefore, prolonged service life.