In this study， whey protein enzyme hydrolysate was obtained by the combined treatment of proteolysis and lactic acid bacteria fermentation. The volatile flavor compounds of enzyme hydrolysate were analyzed by gas chromatography and mass spectrometry， and the immunomodulatory activity of enzyme hydrolysate was evaluated by mouse spleen lymphocyte model. The results showed that the fermentation of lactic acid bacteria improved the relative content of esters and acids， and reduced the relative content of 6-gingerol and other unpleasant flavor substances in the hydrolysate. The immunomodulatory activity of whey protein was significantly improved after proteolysis， and the stimulation index of whey protein enzyme hydrolysate was 1.45±0.06 at the mass concentration of 250 μg/ml. Lactic acid bacteria fermentation had no adverse effect on the immunomodulatory activity of whey protein enzyme hydrolysate. The molecular weight of fermented whey protein enzyme hydrolysate was mainly between 0 to 3 ku， accounting for 66.07%. The results of this study indicated that the combined treatment of proteolysis and lactic acid bacteria fermentation could obtain whey protein enzyme hydrolysate with improved flavor and immunomodulatory activity.