The invention relates to a method for preparing a 
fresh fish essence through processed 
freshwater fish leftover binary 
fermentation. The method comprises the following steps: (1) crushing, namely crushing the processed 
freshwater fish leftover to be 40-60 meshes; (2) endogenous enxymolysis, namely activating fish 
cathepsin through ph and 
temperature control and Ca<2+>, appropriately hydrolyzing fish 
protein, and reducing the 
system viscosity; (3) sterilizing and curing, namely adding 
lentinus edodes stem 
powder, heating at 121 DEG C for 30 minutes, steering and 
softening fish bones, and stimulating 
calcium and 
bone collagen to dissolve out; (4) inoculated 
fermentation, namely inoculating a high-temperature 
yeast and 
lactobacillus bulgaricus binary 
fermentation agent to ferment; (5) homogenizing; (6) concentrating; and (7) after 
ripening. The method has the advantages that a problem that the processed 
freshwater fish leftover is difficult to utilize is solved; a product is stable in taste, natural in 
flavor, rich in 
nutrition and rich in various beneficial ingredients; and a production technology is unified, simple and easy to standardize.