The invention discloses an antibiotic disinfectant for garment fabric and a preparation method of the antibiotic disinfectant. The antibiotic disinfectant is prepared from, by weight part, nano-silver loaded SiO2 particles, polylactic acid, sodium carboxymethyl cellulose, tebuconazole, difenoconazole, choline chloride, chitosan propionic acid, bromo-geramine, vermiculite powder, nitroethane, a coupling agent, an antioxidant, a dispersing agent, surfactant, isopropyl alcohol and deionized water. The antibiotic disinfectant is high in safety, the broad-spectrum antibacterial property and excellent laundering durability are achieved, no bad influence exists on whiteness, color light, strength, hand feeling and air permeability of the fabric, the price is low, use is convenient, the antibiotic disinfectant is suitable for antibiotic and odor resistant finish of fabric such as down, cotton, silk, wool, polyester cotton and viscose, the hand feeling is fluffy and soft, composition design is reasonable, the production cost is low, and the economic benefit is good.