The invention discloses a traditional Chinese medicine preparation for treating bacterial enteritis of sea fish, prepared from the following components in weight: 10-30g of coptis root, 10-20g of Chinese pulsatilla, 10-20g of kuh-seng, 10-20g of charred hawthorn, 10-20g of stemona root and 10-20g of nutgall. The preparation method comprises the steps of: respectively pulverizing each component into powder of 300 meshes, and then mixing uniformly. The invention has the advantages of stable sources of raw materials, reliable quality, simple production process, relatively low price and high curerate for bacterial enteritis of sea fish.