The invention relates to a preparation method of an anti-freeze soy isolate 
protein. The preparation method comprises the following steps of: 1, modification: adding water into a soy isolate 
protein to dissolve the soy isolate 
protein into an 18 to 20% soy isolate 
protein solution, carrying out normal pressure heating under the condition of 85 to 95 DEG C for 15 to 20min, and adjusting the pH value to a neutral value to obtain modified soy isolate 
protein solution; 2, mixing: adding collagen 
hydrolysate and coconut meat extract which account for 5 to 15% of the total weight of the modified soy isolate 
protein solution into the modified soy isolate protein solution, uniformly stirring, shearing and homogenizing to obtain 
mixed solution; wherein the weight ratio of the collagen 
hydrolysate to the coconut meat extract is 2: 1; and 3, 
drying: carrying out normal pressure storage on the 
mixed solution under the condition of a water bath of 40 DEG C to 50 DEG C for 1 to 2 hours, after cooling to the 
room temperature, standing for 10 to 20 minutes, and carrying out 
spray drying to obtain the anti-freezing soy isolate protein. The preparation method provided by the invention is mild in modification condition, simple in process, easy to operate and short in production time, does not require complex equipment, and has the wide industrial application prospect.