Rotavirus (RV) is one of the main pathogens causing diarrhea in children under five years old, but the mechanism of RV-infected diarrhea is still unclear. The RV genome encodes six structural proteins (VP1-VP4, VP6 and VP7) and six non-structural proteins (NSP1-NSP6), among which NSP4 can interact with other non-structural proteins or structural proteins of RV to produce corresponding biological functions, and is a key factor in the formation of RV morphology, the process of infection and the pathogenesis of diarrhea. In this paper, the current domestic and foreign studies on the structure and function of NSP4 are reviewed.