In recent years, with the increasing volume of related research, it has become apparent that the liver and gut play important roles in the pathogenesis of neurological disorders. Considering the interactions among the brain, liver, and gut, the brain–liver–gut axis has been proposed and gradually recognized. In this article, we summarized the complex network of interactions within the brain–liver–gut axis, encompassing the vagus nerve, barrier permeability, immunity and inflammation, the blood–brain barrier, gut microbial metabolites, the gut barrier, neurotoxic metabolites, and beta-amyloid (Aβ) metabolism. We also elaborated on the impact of the brain–liver–gut axis on various neurological disorders. Furthermore, we outline several therapies aimed at modulating the brain–liver–gut axis, including antibiotics, probiotics and prebiotics, fecal microbiota transplantation (FMT), vagus nerve stimulation (VNS), and dietary interventions. The focus is on elucidating possible mechanisms underlying neurological disorders pathogenesis and identifying effective treatments that are based on our understanding of the brain–liver–gut axis.