The invention relates to the field of fish foodstuff 
processing, in particular to instant cold sour fish and a preparation method thereof. The cold sour fish comprises, by weight, 95-105 parts of fillets, 1-2.5 parts of salt, 0.05-0.5 part of citrus cooking 
wine, 0.02-0.6 part of citrus 
seasoning vinegar, 0.01-0.4 part of citrus fish 
steaming extract, 0.5-5 parts of mixed sauce, 2-3 parts of 
staphylococcus xylosus liquid and 1-2 parts of 
mixed culture liquid of 
lactobacillus plantarum and 
pediococcus acidilactici, wherein the salt, the citrus cooking 
wine, the citrus 
seasoning vinegar and the citrus fish 
steaming extract serve as curing materials. The cold sour fish is manufactured through the steps of vacuum rolling, malaxating and curing, 
cold air drying, freezing, 
settling and slitting, curing and 
fermentation, vacuum 
package and cold sterilization. According to the instant cold sour fish and the preparation method thereof, the unique citrus 
fish extract, the citrus cooking 
wine and the citrus 
seasoning vinegar are adopted, the citrus added value is increased, technologies such as small-patch 
inoculation, segmented inoculated 
fermentation cultures, 
fermentation while ventilation and vacuum 
package are adopted, so that the producing time of the produced cold sour fish is shortened, 
flavor substances of the product are abundant, and the industrialized production of tradition foodstuff is achieved.