Abstract: Konjac glucomannan (KGM), a hydrocolloid polysaccharide dietary fiber extracted from konjac tubers, is characterized by its remarkable swelling properties and biological functions. As a natural functional polysaccharide, KGM plays a crucial role in metabolic disorders such as lipid reduction and blood sugar regulation. In recent years, its regulatory effects on the nervous system have gained growing research interest. This review systematically elaborates on the bioactivities of KGM in relation to the nervous system, the “gut-brain” axis, and its applications in neuro-related diseases. Additionally, it prospects the future research and development directions, providing a scientific reference for theoretical exploration and practical applications in this field.