The invention discloses a preparation method and an application in double protein snack food for dried fish. The preparation method for the dried fish comprises the following steps: pretreating raw materials, salting and removing fishy, seasoning and boiling, air frying, and drying. The double protein snack food is made of the dried fish, walnut seeds, peanuts, broad beans, bitter apricot seeds, cashew nuts, Siberian filbert seeds, pumpkin seeds, raisins, dried bananas, dried cranberries, and dried blueberries. The preparation of the dried fish combines the air frying and drying processes to change a traditional high-temperature frying process, a crispy taste of traditional frying is maintained, nutrients of the raw fishes are also maintained, and the oil content is also reduced. In the double protein snack food, nutrients of animal and plant protein are complemented, a special flavor of nuts and dried fruit products and nutrients of high vitamins and high minerals are combined, the dried fish is a new type of nutritious and healthy snack food, is provided with characteristics of high animal and vegetable protein, low oil content, high vitamin and mineral content, crispy taste, andthe like, and has good market prospects.