A preparation method of a nanozyme composite-based hybrid hydrogel eye drop includes synthesizing a tannin-coordinated silver/cobalt composite nanoparticle through a coordination reaction of cobalt chloride hexahydrate with ammonia water and an oxidation-reduction reaction of silver nitrate with tannin; and mixing the silver/cobalt composite nanoparticle with an acrylate-modified gelatin, conducting an ultrasonic treatment to allow complete dissolution, and irradiating a resulting mixture under ultraviolet (UV) light to obtain the nanozyme composite-based hybrid hydrogel eye drop. The preparation method of the present disclosure has simple operations and a short preparation time. The eye drop prepared by the preparation method shows a broad-spectrum bactericidal effect against a variety of bacteria and fungi, and has prominent preventive and therapeutic effects for bacterial and drug-resistant bacterial corneal infections.