The invention relates to fermented 
soybean meal and a preparation method thereof. The preparation method of the fermented 
soybean meal comprises the following steps: crushing peeled 
soybean meal and performing sieving with an 80-mesh 
sieve, carrying out first-step enzymolysis by using alpha-galactosidase and glucoamylase, then carrying out second-step enzymolysis by using 
papain, carrying out 
enzyme deactivation, inoculating a composite strain of 
saccharomycetes, bacillus and 
lactic acid bacteria, carrying out aerobic 
fermentation, then carrying out anaerobic 
fermentation, and carrying out 
spray drying on the finished product to retain active ingredients to the maximum extent. The prepared enzymatically hydrolyzed and fermented soybean 
meal has specific fragrance of 
fermentation, the 
protein content is about 55%, and the acid-soluble 
protein content is greater than 50%. Antinutritional factors such as antigens are basically removed, and the components are stable. The enzymatically hydrolyzed and fermented soybean 
meal has the characteristics of strong hydrophilicity, high 
water retention rate, high 
palatability, obvious phagostimulant to aquatic animals and the like. The fermentedsoybean 
meal is rich in functional small peptides, probiotics and metabolites of probiotics, is beneficial to intestinal 
nutrition balance of cultured animals, can be used to solve the problem of nutritional 
diarrhea of animals, and is suitable for feed for piglets, poultry, pets, aquatic products and the like, wherein the suggested use ratio is 2-5%.