Beta-lactoglobulin (β-LG) is one of the most important allergens in whey protein. How to reduce the antigenicity of β-LG is a problem that needs to be solved. In this paper, alkaline proteinase, trypsin or their combination was used to hydrolyze whey protein, and samples were taken at different hydrolysis times. The degree of hydrolysis and molecular mass distribution of the hydrolysate with the lowest antigenicity of β-LG were analyzed, and its bitter taste was compared with that of two commercial hydrolyzed whey protein products. Overall, hydrolysis of bovine whey protein with a mixture of alkaline protease and trypsin (1:1, m/m) produced products with low bitterness and antigenicity (0.798 μg/mL). The process parameters were as follows: substrate concentration 15 g/100 mL, enzyme to substrate ratio 5 000 U/g (50% alkaline protease plus 50% trypsin), initial pH 8.0, and hydrolysis for 2.5 h at 48 ℃.