The invention discloses a fluorinated polyurethane thickener applied to supercritical CO2 tackification and a preparation method thereof, belongs to the field of petrifaction, and in particular relates to a thickener for supercritical CO2 dry-method fracturing and a preparation method thereof. The invention aims to provide the thickener special for supercritical CO2 dry-method fracturing and the preparation method thereof, wherein the thickener has good tackifying performance, can be easily dissolved in CO2 fluid, and has a stable system. The thickener is prepared from the following components in parts by fraction: 10 to 15 percent of diisocyanate, 5 to 8 percent of polyethylene glycol, 5 to 8 percent of trimethylolpropane, 1 to 2 percent of catalyst, 1 to 2 percent of initiator, 3 to 5 percent of sorbitan polyoxyethylene ether, 3 to 5 percent of perfluor octyl ethylene, 3 to 5 percent of dodecafluoroheptyl acrylate, and the balance of castor oil. The thickener has good tackifying performance, can be easily dissolved in the CO2 fluid, and has the stable system.