Abstract: In this study,the allergenicity,protein molecular weight,degree of hydrolysis and amino acid composition of soy milk powder under different enzyme-assisted aqueous extraction time conditions were studied. The atomic force microscope and Raman spectroscopy were used to analyze the structural changes of soybean milk powder protein. The results showed that enzyme-assisted aqueous extraction could effectively reduce the allergenicity of soy milk powder,and the lowest allergen content was 1.80 mg/g.As the biological dissociation time increasing,the degree of hydrolysis increased and the molecular weight of protein decreased. When the enzyme-assisted aqueous extraction time was 30 min,the maximum degree of hydrolysis was 13.2%. Atomic force microscope observation showed that the protein existed in a single molecular state and no molecular aggregation occurred at 20 min of enzyme-assisted aqueous extraction. Raman spectroscopy analysis showed that the chemical bonds and groups in the protein were damaged to some extent.