The invention discloses a medicine for fish without chemical injury, which is not made from medicines with high toxicity, but utilizes traditional Chinese medicine with low toxicity to destroy parasites and sterilize. Added with alexipharmic synchronously, the medicine has the functions of destroying parasites, sterilizing, and removing toxic substances, without hurting fish. Tryouts from place to place prove that the fish has no chemical injury, the fish bile is normal bile-yellow, and the fish has no toxic and side effect reaction. Attending, destroying parasites, sterilizing, removing toxic substances and diminishing inflammation; wherein, stopping the bleeding, relieving diarrhea, diminishing inflammation for trauma, promoting granulation, promoting digestion and increasing appetite powerfully, generating blood to promote growth, keeping the fish body identical cyan, improving the high activity, being suitable for long transportation. The medicine has special effect for a plurality of diseases. The medicine has the advantages of convenient application, high cure rate, great fish appetite, fast growth, few diseases, high yield, no toxic or side effect with fish, transforming to green fish food step by step. Application process: putting the medicine on the food plain stage according to the dosage in the instruction book and the size of the fish pond. Note: overdose, the fish appetite is too great; the fish must be fed according to quantity, otherwise, the fish is distensible to death, water quality is polluted seriously, chemical injury is severe, fish diseases are near to afternoon, difficult to prevent and cure.