Onitrazole and levofloxacin can be used in combination when there are therapeutic indications, such as sensitive gram-negative or positive bacterial infections, and at the same time there are anaerobic infections can be used in combination. Ornidazole is a typical nitroimidazole antibiotic, in killing anaerobic bacteria, relieve anaerobic infections have a very obvious effect, but single use of ornidazole drug treatment, not only to increase the patient’s chances of adverse reactions, but also may lead to the emergence of bacterial resistance. Therefore, more often take the method of combined treatment. The combined use of levofloxacin can reduce the side effects and drug resistance formation that may be caused by long-term use of ornidazole, in addition, levofloxacin’s antimicrobial effect and efficacy of the stability of the strong, can be used to treat a number of systems such as the respiratory system, the digestive system, the skin and soft tissues of the gram-negative and gram-positive bacterial infections, the use of drugs with high safety and efficacy, can minimize the treatment time. Whether ornidazole and levofloxacin are used in combination needs to be judged according to the type of bacterial infection, the infected system and bacterial drug sensitivity results, and needs to be used under the guidance of a physician, do not use the drug on your own, so as not to cause adverse consequences.