The invention discloses an anti-infection high-strength absorbable medical suture and a preparation method thereof. The raw materials of the medical suture include: polycaprolactone, polyglycolic acid, β-chitosan, phenylalanine, silkworm chrysalis shell powder , Propolis, Carbomer, Polyoxyethylene, Polyvinylpyrrolidone, Polyvinyl Alcohol, Plant Extract Containing Centella Asiatica, Polyhexamethylene Biguanide, Sorbitol, Tween 60. The absorbable medical suture prepared by the invention has a good healing effect on wounds, and the straight pull strength, knot strength and elongation at break are all significantly improved, and the healing rate is as high as over 98%, without complications and infection. In addition, the prepared absorbable medical suture has good absorption performance, good biocompatibility, and good clinical application value, which is worthy of popularization and application.