The invention belongs to the technical field of aquatic product processing, and particularly relates to a processing method of a prefabricated loach dish, which comprises the following steps: unfreezing, cleaning, deodorizing, frying, pickling to be tasty, vacuum packaging and microwave sterilizing. The raw material comprises loach, salt, green onion, ginger, black pepper powder, cooking wine, white spirit, garlic, chili, soybean oil, salad oil, lard, monosodium glutamate, white sugar, vinegar, soy sauce, green and red rice pepper, onion, soybean paste, chilli sauce, minced garlic sauce, amomum tsao-ko, anise, cinnamon, myrcia, netmeg, chive, water, plumeria rubra extract, golden camellia flower extract, rosemary extract and lysozyme. The method has the beneficial technical effects that the loss of nutrient substances caused by high-temperature processing is greatly reduced, active ingredients with nourishing functions in the loaches are reserved, and the product is rich in taste, reasonable and scientific in formula and capable of nourishing the body.