The invention discloses a Chinese herbal medicine preparation for preventing and treating oncorhynchus mykiss enteritis. The Chinese herbal medicine preparation is made of the following raw materials:epimedium herb, hedyotis, Chinese lobelia herb, maple leaf, acalypha australis, plantain herb, heartleaf houttuynia herb, solomonseal rhizome, milkvetch root, perilla leaf, senecio scandens, malayteascurfpea fruit, Tokyo violet herb, Indian bread, glossy privet fruit, corn whisker, and a complex bacterial agent. In the preparation, epimedium herb, maple leaf, acalypha australis, heartleaf houttuynia herb, solomonseal rhizome, milkvetch root, perilla leaf and the like can have sterilization and disinfection effects, plantain herb, senecio scandens and the like can have anti-bacteria and anti-inflammation effects, malaytea scurfpea fruit and Tokyo violet herb can promote the increase of a number of white blood cells in the blood, Indian bread, glossy privet fruit and the like can improve the immunity of fishes, corn whisker and the like have effects similar to an interferon, epimedium herb and the like can promote antibody production, and hedyotis, Chinese lobelia herb and the like canstimulate tumor immune response. Each drug complements each other and promotes each other to achieve prevention and treatment of oncorhynchus mykiss enteritis. The Chinese herbal medicine preparationcontains bacteria that are beneficial to the oncorhynchus mykiss gastrointestinal tract, and intestinal peristalsis is promoted, so that the occurrence of gastrointestinal diseases is reduced.