The invention discloses a compound feed for Scylla serrata, comprising fish meal, shrimp head powder, soybean meal, rapeseed meal, fish oil, soybean phosphatide powder, brewers yeast, choline chloride, molt hormone, bread flour, calcium dihydrogen phosphate, sodium dehydroacetate, butyl hydroxy anisole, astaxanthin, Schizochytrium limacinum, Bacillus licheniformis, a composite feeding promoting agent, a complex vitamin additive, a composite mineral matter additive and a composite adhesive. The feed has balanced nutrition, is resistant to spoilage, has a long storage life, not only reduces feed cost but also promotes the growth and improves the color of the Scylla serrate. In addition, the feed is friendly to environment, has good palatability and feed promoting effect, has high utilization efficiency and good stability in water, and can enhance the immunity and survival rate of scylla serrata. The invention also provides a preparation method for the compound feed for scylla serrata, which is simple in technology, with the function substance in raw material undestroyed in the preparation process.