Abstract: Based on the literature review on exercise mediated gut and brain connectivity, the effects of appropriate exercise and overtraining on gut function, neural conduction of gut-brain axis, and biological signaling molecules are analyzed, in order to reveal the underlying mechanism. It is found that there is a close interaction between the gut and brain, and the bidirectional neural connections and related biological signaling molecules between the gut-brain axis are mediators for achieving crosstalk between the gut and brain. Exercise can regulate the neural connections and related biomolecules between the gut and brain, affecting the gut-brain axis, mediating its health, as well as the prognosis of neurological and psychiatric diseases. Gut microbiota is an important participant in achieving information communication between the gut-brain axis. Exercise regulates gut function and gut-brain axis by regulating the gut microbiota, as well as the changes in neural transmission pathways and biological signaling molecules to exert terminal effects, thereby affecting advanced neural function. However, there are significant differences in the regulatory effects of different intensities of exercise on gut microbiota and gut-brain axis, and the intervention results caused by appropriate exercise and overtraining are completely different.