The role of morphine for the central nervous system has the following aspects: 1, the role of analgesia and sedation, morphine for analgesia is mainly for chronic dull pain, such as cancer-induced pain, it can significantly reduce and eliminate pain, and acute myocardial infarction analgesia, sedation, but the consciousness of the patient is not affected. Morphine’s sedative effect is mainly to relieve because of various pain, caused by the tension, anxiety, it can improve the tolerance of pain, thus reducing the emotional impact of patients on pain. 2, morphine can inhibit the respiratory center, mainly acting on the respiratory center, can make the respiratory slowdown, inhibit the role of the respiratory center, mainly to reduce the sensitivity of the respiratory center to blood carbon dioxide tension, in addition to the bridge brain 3, morphine can inhibit the cough center, with a central cough suppressant effect. 4, morphine can act on the pupil regulation center, causing the pupil to narrow, generally after morphine poisoning patients show pinpoint pupils.