The invention discloses a microbial preparation, an aquatic feed and an aquaculture method and relates to the technical field of aquaculture. The microbial preparation comprises bdellovibrio and probiotic. Optimally, the probiotic is selected from any one of lactobacillus bulgaricus, lactobacillus delbrueckii, enterococcus faecalis, lactobacillus casei, lactobacillus acidophilus, rhodopseudomonaspalustris, clostridium butyricum, bacillus laterosporus, bacillus pumilus, bacillus coagulans, bacillus licheniformis, bacillus subtilis and lactobacillus plantarum. The microbial preparation has thecharacteristics of capability of increasing food intake of aquaculture animals, capability of promoting growth rate, survival rate and immunity of organisms, and the like. Besides, the microbial preparation is capable of effectively preventing and treating the problems of diseases caused by pathogenic bacteria, such as vibrio parahaemolyticus, vibrio harveyi, luminous vibrio, vibrio alginolyticus,vibrio campbellii, vibrio fluvialis, vibrio vulnificus, aeromonas, vibrio cholerae, pseudomonas and salmonella.