The present invention relates to the field of 
biotechnology and particularly relates to a method for preparing a soybean Aglycin family 
peptide by using 
acetic acid. The method for preparing the soybean Aglycin family 
peptide by using 
acetic acid comprises the following steps: subjecting raw materials to cleaning, soaking, 
germination, 
grinding and extraction, separating the 
slag from the 
slurry through a 
ceramic membrane and an organic membrane, and subjecting obtained materials to freeze-
drying. According to the technical scheme of the invention, the 
acetic acid is extracted from soybeans, and the 
ceramic membrane and the organic membrane are combined to use, wherein the pore size of the 
ceramic membrane is 0.1 [mu]m and the pore size of the organic membrane is 1500 D to 6000 D. In this way, small 
protein and polypeptide compounds, with the molecular weight thereof between 1500 D to 6000 D, are obtained. The method is simple in operation, thoroughly in extraction effect, easy in 
filtration, short in 
production cycle, greatly improved in yield and greatly reduced in production cost. Therefore, the industrial production is easily realized. A produced Aglycin product is in the form of light yellow powders, and is good in taste and high in purity. The Aglycin product can be used as 
functional food for the 
adjuvant therapy of type 2 diabetes for preventing diabetes.