NOVELTY - Aquatic probiotic bacteria sea fertilizer preparation comprises mixing dried chicken manure, rice bran, EM bacteria liquid, brown sugar, and water at 45:30:2:1:22 ratio by stirring; pouring the mixture into fermentation pit, sealing to ferment for 10-15 days, drying, pulverizing, and screening with 80 mesh screen to obtain organic compound bacteria additive; and mixing the organic compound bacteria additive, potassium nitrate powder, sodium silicate powder, iron citrate powder, and sodium ethylene diamine tetraacetate powder at 46:30:20:2:2 ratio.    USE - For preparing aquatic probiotic bacteria sea fertilizer useful for marine microalgae.    ADVANTAGE - The fertilizer is environment-friendly, inhibits the breeding of harmful algae with an effect of fertilizing water quickly, increases dissolved oxygen in water, purifies sediment, and improves water quality at the same time. The sea fertilizer bacteria are in dormant state, stable, and easy to preserve. When put into water, the dormant bacteria can revive and disintegrate fast and breed to predominant flora to quickly break up the organic contaminants and remove harmful substances in water, such as amino nitrogen, nitroso nitrogen, and hydrogen sulfide, transforming into nutritional source for marine unicellular algae.    DETAILED DESCRIPTION - Aquatic probiotic bacteria sea fertilizer preparation comprises drying fresh chicken manure in shade and collecting when the moisture content is 18-20%; screening rice bran with 60 mesh screen; providing EM bacteria liquid; mixing dried chicken manure, rice bran, EM bacteria liquid, brown sugar, and water at 45:30:2:1:22 ratio by stirring; pouring the mixture into fermentation pit, sealing to ferment for 10-15 days, drying, pulverizing, and screening with 80 mesh screen to obtain organic compound bacteria additive; screening potassium nitrate powder, sodium silicate powder, iron citrate powder, and sodium ethylene diamine tetraacetate powder with 80 mesh screen; and mixing the obtained organic compound bacteria additive, potassium nitrate powder, sodium silicate powder, iron citrate powder, and sodium ethylene diamine tetraacetate powder at 46:30:20:2:2 ratio.