The invention discloses a pharmaceutical composition and application for alleviating or eliminating opioid withdrawal syndrome. The pharmaceutical composition comprises clonidine hydrochloride and tramadol hydrochloride with a mass ratio of 0.01-0.8:40-60, and the Application of the pharmaceutical composition in the preparation of drugs for alleviating or eliminating opioid withdrawal syndrome. The present invention is more suitable for the detoxification of patients with opioid drug abuse, with good effect, short time, 3-5 days to complete, safe and effective, easy to operate, has obvious clinical advantages and curative effect, and can improve patients' medication compliance and medication experience, Prevent abuse.