The present invention discloses a preparation method of a parental fish feed containing spirulina platensis powder. Dry materials and wet materials are firstly separately prepared and then mixed at a ratio of 7: 3. The dry materials contain the following components at the following ratio: 80-95 parts of pre-gelatinized starch, 5-15 parts of spirulina platensis powder, 0.3-0.9 g/t of selenium yeast powder, 0.1-0.3 part of composite additive, 30-50 g/t of choline chloride, and 80-100 g/t of bile acids; and the mixed mode follows the principle of progressively enlarging, and small materials are mixed evenly with large materials to conduct progressively enlarging. The composition ratios of the wet materials are as follows: pig afterbirths 30-40 parts, fresh earthworms 3-9 parts, fresh coarse fish 50-70 parts, and the wet materials are prepared by being mixed and minced together. The parental fish feed has simple and easy-to-get raw materials, and cheap price, is nutritionally balanced, has high protein content, and can enhance the gonadal development of the parental fish, enhance the quality of gametes, and ultimately improve the reproduction rate and quality.