The invention relates to a preparation method of instant 
fresh water fish 
peptide powder. By using 
fresh water fish as raw materials, the preparation method comprises the following steps: removing 
fish skin and fish belly fat by a 
skin remover and a cube cutter, and then removing fishy smell and partial fat of the fish by using the technology of soaking with a mixture of CaCl2 and C2H4O2; then adding 
papain and 
Bacillus subtilis neutral proteinase for 
hydrolysis, carrying out inactivation and 
degreasing by the superhigh pressure technology, and separating 
slag from liquid by utilizing a 
centrifuge; and then adding 
activated carbon to the 
hydrolysate for bitterness and fishy smell removing treatments, filtering by utilizing a plate and frame 
filter press, concentrating the obtained filtrate in vacuum, and carrying out 
spray drying to obtain the instant 
fresh water fish 
peptide powder. The product prepared by the method has the characteristics of water 
solubility, creamy white color, palatefullness, no fishy smell and the like, and no organic 
reagent is used in the entire production process flow. The product is rich in 
small peptide, 
oligopeptide and various amino acids, can be used for manufacturing nutriment food for infants, advanced nutriment and health products for adults and the like, and also can be used as the ingredient for preparing advanced nutriment 
peptide coffee, flavorings and the like.