In order to prepare original material for developing low phenylalanine special food, the peanut protein was degraded by Alcalase2.4L and papain, the hydrolysis by Flavourzyme and the removal of phenylalanine by activated carbon were determined by signal and orthogonal tests separately. The optimal parameters were found to be hydrolysis temperature 50 ℃, pH 6.5, enzyme/substrate 3 500 U/g and time 5 h, which resulted in a content of free phenylalanine of 28.65 mg/100 mL in hydrolysates. The removal of phenylalanine with 7 g/100 g activated carbon powder was conducted at 35 ℃, pH 3.0 for 2.5 h and the removal rate of phenylalanine could reach 98.64% under these parameters. The amino acids and molecular weight analysis showed a significant decrease for the content of phenylalanine (0.61 mg/100 mL) and the molecular weight was blow 600 Da, mainly including oligopeptides and free amino acids. The resulting product could be used to prepare special medical formula foods in the future.