The role of methadone has two main points: First, it can be used for trauma, post-surgery, advanced tumor and other pain, as well as severe pain caused by various reasons, can be applied to symptomatic treatment of methadone, it is a synthetic narcotic drugs, addiction is very small. Second, methadone can help detoxification, especially for a variety of opioid poisons can be abstinence, more common is morphine, dulcolax, opium and so on. Methadone is less addictive and can be used in a gradual reduction manner to help patients complete detoxification. However, methadone should be strictly managed and can only be applied in isolated detoxification wards, requiring a doctor to strictly grasp the indications.