The invention discloses a method for preparing a superhydrophobic cotton textile by thiol-ene click chemistry modification. The method comprises the following steps of Step 1, pretreating cotton fabrics so that thiol groups are introduced to the fiber surfaces; Step 2, grafting thiol silane onto the surfaces of the pretreated cotton fabrics; and Step 3, soaking the cotton fabrics grafted with thethiol silane into a mixed solution prepared from ethyl acetate, 2,4,6,8-Tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, octadecanethiol and benzoin dimethyl ether to take a reaction through UV irradiation, and after the reaction is completed, performing cleaning and drying to obtain the superhydrophobic cotton textile. The invention also discloses the superhydrophobic cotton textile prepared bythe method. The superhydrophobic cotton textile prepared by the method provided by the invention has the advantages that hydrophobic substances are grafted onto the surfaces of the fabrics in a chemical bond form; and the performance of resisting acid, alkali, water washing, friction, UV irradiation and the like of the superhydrophobic textiles can be improved.