The present invention discloses a micro-organism compounding and mixing agent. The micro-organism compounding and mixing agent is characterized by being prepared by the following steps: photosyntheticbacteria, nitrobacter, nitrosobacter, bacillus, lactobacillus, yeasts, actinomycetes, seabuckthorn freeze-dried powder, roxburgh rose freeze-dried powder, wintercherry freeze-dried powder, blackcurrant freeze-dried powder and cactus freeze-dried powder are evenly mixed; then a remaining amount of charred eggshell powder is added; the materials are evenly mixed; and the mixture is compound-packaged to prepare the micro-organism compounding and mixing agent. Every 1,000 g of the micro-organism compounding and mixing agent contains 600 billion-5,000 billion of photosynthesis bacteria, 500 billion-1,000 billion of nitrobacter, 5,00 billion-1,000 billion of nitrosobacter, 5,00 billion-1,000 billion of bacillus, 5,00 billion-1,000 billion of lactobacillus, 5,00 billion-1,000 billion of yeasts,5,00 billion-1,000 billion of actinomycetes, 5-50 g of seabuckthorn freeze-dried powder, 5-50 g of roxburgh rose freeze-dried powder, 3-30 g of wintercherry freeze-dried powder, 3-30 g of blackcurrantfreeze-dried powder, 50-100 g of cactus freeze-dried powder, and the balanced charred eggshell powder. The seabuckthorn, roxburgh rose, wintercherry, blackcurrant and cactus freeze-dried powder and charred eggshell powder are used as the matrix, so that the micro-organism compounding and mixing agent can regulate internal and external environment of aquatic animals and can also enhance the disease resistance of the aquatic animals.