Abstract: The gut microbiota is an intricate and dynamic community composed of many symbiotic and pathogenic microorganisms, and works closely with the host. In recent years increasing evidence has supported the gut-brain axis theory, lending support for a link between gut microbiota and neuropsychiatric diseases. Since most of the drugs used to treat neuropsychiatric diseases enter the intestinal tract after oral administration, interaction with the gut microbiota is likely. A number of studies have shown that such drugs can change the composition and function of the gut microbiota. At the same time, the gut microbiota also participates in the metabolism of drugs, which in turn have beneficial or harmful effects on brain function. Therefore, the role of gut microbiota in drug metabolism also has attracted attention. This article reviews the research results of the interaction between the two, discusses the influence of neuropsychiatric diseases on the gut microbiota and the effect of the gut microbiota on psychoactive drugs, and provides new ideas for the treatment of various clinical neuropsychiatric diseases.