The difference between tinidazole and ornidazole can be analyzed through clinical application, adverse reactions and precautions. 1. Clinical application: Tinidazole can be used for various infections induced by anaerobic bacteria, such as abdominal surgery, gynecological surgical trauma, periodontitis, sepsis, and soft-tissue skin infections, etc.; Ornidazole is generally used in the treatment of periorbital cellulitis and Giardia lamblia, etc., and it can be used for the prevention of infections induced by abdominal surgery. 2. Adverse reactions: Tinidazole has relatively more adverse reactions, including dizziness, headache, gastrointestinal discomfort, allergic reactions, neurological symptoms and secondary infections, etc.; Onitrazole has relatively fewer adverse reactions, including dizziness, headache, allergic reactions and gastrointestinal discomfort. 3. Precautions: Tinidazole can not be used in pregnancy and lactating women, and can not be used in patients with a history of hematological diseases and organic neurological diseases; ornidazole can not be used in early pregnancy and ornidazole allergic patients. In addition, the application of the above drugs have certain risks, patients need to get the guidance of a specialist.