The invention provides a stichopus japonicus puffing feed added with enteromorpha prolifera, and a preparation method of the feed, belonging to the technology of preparation of the stichopus japonicus puffing feed. The stichopus japonicus puffing feed is prepared by adding enteromorpha prolifera dry powder. The stichopus japonicus puffing feed comprises the following ingredients in percent by mass: 4-8% of defatted fishmeal, 6-10% of cerevisiae fermentum, 15-25% of enteromorpha prolifera powder, 25-35% of seaweed meal, 5-7% of sea mud, 16-20% of strong flour, 5-7% of soybean meal, 3-5% of fish oil, 1% of vitamin complex and 1% of compound microelement; and in addition, 2-4% of zeolite powder and 0.5% of probiotics can be added. The stichopus japonicus puffing feed is prepared by adopting the puffing process, is high in nutrition digestibility and low in feed coefficient, and is reduced in the incidence of digestive tract diseases of intestines and stomach, remarkably enhanced in the survival rate of the stichopus japonicus, promoted in the rapid growth of the stichopus japonicus; and by adopting the enteromorpha prolifera powder to replace sargassum thunbergii powder, gulfweed powder, and the like, the feed has rich raw materials and is low in cost.