The invention discloses freezing-resisting soybean protein isolate and a preparation method thereof, and belongs to the technical field of soyabean protein processing. According to the freezing-resisting soybean protein isolate and the preparation method, degreased soybean meal is taken as a raw material, and the freezing-resisting soybean protein isolate is prepared through processes of alkali dissolution, acid precipitation, redissolution, gelatin mixing, enzyme crosslinking, spray drying and the like. The soybean protein isolate can improve the gel texture or reduce deterioration of sensory quality of frozen foods due to frozen storage. According to the freezing-resisting soybean protein isolate, the water holding rate of protein gel can still be higher than 85% in one-month frozen storage period. According to the method, an enzyme crosslinking method is adopted for modifying the soybean protein isolate, the modification condition is mild, the process is simple, the operation is easy, the production time is short, complicated equipment is not required, the prominent realistic problem of related food quality deterioration caused by the fact that the water holding capacity of protein gel is reduced under the extreme low-temperature condition when soybean protein isolate is added and used into the frozen foods at presence is better solved, and the freezing-resisting soybean protein isolate has wide industrial application prospect.