Disclosed are a protein hydrolysate and a preparation method thereof, which the method is to mix two different enzymes, and heat the mixture with the protein in two stages for hydrolysis, thereby increasing hydrolysis rate of the protein hydrolysate and reducing the time of reaction.本發明之蛋白水解液及其製備方法,其係利用二種不同酵素混合,並利用二階段升溫之方式與蛋白進行水解,藉以提高蛋白水解液之水解率與降低作用時間。