The invention relates to the field of good 
biotechnology, and particularly relates to a preparation method of 
egg white powder from 
dipeptide-pentapeptide. According to the preparation method, fresh 
egg white is subjected to thermal denaturating treatment and continuous fractional 
hydrolysis to obtain an 
egg white oligopeptide solution formed by 
dipeptide-pentapeptide, wherein the 
hydrolysis process in the first step is completed by adopting 
protease with the optimum pH being within the alkaline scope, and the 
hydrolysis process in the second step is completed by adopting 
protease with the optimum pH being within the neutral scope; and the egg 
white powder product is obtained by performing first-step refining for debittering and vacuum concentration with beta-
cyclodextrin and second-step refining for deodorization and 
drying on the egg white 
oligopeptide solution. The method disclosed by the invention has the advantages of being less in equipment investment and high in product yield; the 
total protein content of the egg 
white powder product is higher than 90%, wherein the proportion of the content of 
dipeptide-pentapeptide in the 
total protein is higher than 80%, the ash content islower than 6.5%, the average molecular weight is lower than 1000Da, the 
intestinal absorption and 
utilization rate is high, the 
sensitization is low, the instant 
solubility is excellent, the luster and 
flavor are fine, and therefore, the egg 
white powder is especially suitable for the infants, the old and patients in the 
recovery phase after 
disease and with 
gastrointestinal dysfunction to eat, and can be widely applied to the fields of 
functional food, 
nutritious food and infant food.