As a kind of gas signaling molecules, nitric oxide (NO) is involved in the regulation of diverse physiological functions. In the central nervous system, physiological concentration of NO participates in maintaining physiological neuropsychiatric functions, whereas higher concentrations are neurotoxic, which promote several neuropsychiatric diseases through a wide variety of pathological processes. This review discusses the metabolism and functions of NO in the central nervous system. Taking Alzheimer"s disease, Parkinson"s disease, multiple sclerosis, depression and autism as examples, the relationship and pathogenic mechanism of NO with neurodegenerative diseases, neuroinflammatory diseases, mental disorders and neurodevelopmental disorders are described, which provides ideas and impetus for further development of pathogenic mechanism and therapeutic drugs.