The invention belongs to the technical field of research and development of medical products and relates to a preparation method and application of a compound spirulina formulation. The preparation method comprises the steps of: selecting and cleaning 9-12g of high-quality spirulina, 4-6g of cordate houttuynia, 4-6g of kelp, 4-6g of shiitake mushroom, 4-6g of medlar, 2-3g of truestar anisetree, 2-3g of ginger, 2-3g of garlic, 2-3g of hawthorn, 2-3g of Chinese date and 2-3g of shrimp meal, drying through microwave and grinding into 50-mesh powder, adding water to boil and extract3 times, combining extracts and filtering to obtain filtrate, concentrating the filtrate into extractum, mixing the extractum with starch in a proportion of 1: 4, granulating by using a 10-mesh sieve, drying and screening by using a 14-mesh sieve to obtain the compound spirulina formulation. The product provided by the invention has the function of strengthening the body color of fancy carp and is beneficial for industrialized production.