The invention relates to a durable cotton fabric antifungal finishing method based on click chemistry. The durable cotton fabric antifungal finishing method includes the steps that cotton fabric is coarsened, placed in 1-5wt% of 3-mercaptopropyl triethoxy silane KH-580 solution, vibrated, cleaned and dried to obtain pretreated cotton fabric; the pretreated cotton fabric is soaked in a GTAC solution, the pH value is adjusted to be 6-10, and the cotton fabric reacts for 6-8 h under the stirring condition at the temperature of 30-40 DEG C and is cleaned and dried to obtain the cotton fabric with a durable antifungal function. The method is simple and easy to implement, various original excellent properties of the cotton fabric can be kept, hydrophilic dyeing property is improved while antifungal performance is achieved, and the antifungal finishing method is environmentally friendly, safe, and persistent in effect and has no harm to human body and environment.