Abstract: In order to prepare peanut oligopeptides efficiently, based on the hydrolysis of peanut protein with Alcalase, the influencing factors on the peanut protein hydrolysate of Alcalase enzyme further hydrolyzed by N120P enzyme were investigated. The regression model for the relationship between the impact factors and the yield of oligopeptides was established. Results indicate that the optimal processing conditions for hydrolyzing peanut protein hydrolysate of Alcalase with N120P are as follows: pH value 6.0, time 65 min, temperature 57℃, N120P dosage 2061 U/g. Under the optimal conditions, peanut oligopeptides with the yield of 89.01%, the degree of hydrolysis 23.67%, the average length of peptides 4.21 were prepared. The yield of oligopeptides is 10.86% higher than that of the hydrolysis of peanut protein with only Alcalase. The molecular weight distributiones were determined by High-performance Liquid Chromatography(HPLC). The results indicate that the molecular weights of most oligopeptides are below 1000.