The invention discloses a method for processing an instant sargassum fusiforme (pickle) product by using fresh sargassum fusiforme as well as selection of major raw materials. The preparation process comprises the following steps of: selecting a fresh sargassum fusiforme raw material, cleaning, blanching, cooling, salting, draining, selecting (removing impurities), cutting, desalting and arsenic removal, coarse filtration, dehydrating, finely selecting, preparing, packaging, sterilizing, cooling and packaging; and the following raw materials are selected: preserving and cold-storing salted vegetable, edible oil, gourmet powder, I+G, common salt, white sugar, sesame oil, soy sauce, pepper essence, garlic essence, hot pepper essence, etc. The product disclosed by the invention is abundant in nutrition, quite excellent in mouthfeel, clean and sanitary, free from seaweed fishy smell, ready-to-eat after opening the bag, and convenient to eat. The product, as long as being eaten for a long period, has functions of regulating a thyroid function, resisting coagulation, resisting creotoxin poisoning and tumor, reducing blood pressure, lowering blood lipid and reducing blood sugar.