The invention relates to a fish feed rich in seaweed extract and a preparation method of the fish feed. The fish feed rich in seaweed extract comprises propylene glycol alginate, alginate oligosaccharide, fish meal, blood meal, full-fat silkworm chrysalis meal, rapeseed meal, corn protein powder, wheat flour, full-fat rice bran, compound yeast, liver powder, pine needle meal, bone meal, table saltand other raw materials. The propylene glycol alginate in the feed has high acid and alkali resistance, the alginate oligosaccharide is rich in antibiotic, probiotic and enzyme preparation, is low indosage in the feed, is purely natural, has no residue, is high in stability, and can improve the disease resistance of fishes and shrimps and promote the growth of the fishes and shrimps, and the rawmaterials are excellent feed additives. In addition, the feed contains nutritional ingredients necessary for growth of the fishes and shrimps, contains high protein, improves the immunocompetence ofthe fishes and shrimps, is low in feed coefficient and is beneficial to rapid growth of the fishes and shrimps.