BACKGROUND: Dysfunction of the blood-brain barrier (BBB) is an important pathological mechanism in central nervous system (CNS) diseases and can trigger a series of pathological reactions, such as neuroinflammatory responses, oxidative stress, immune infiltration, etc., thereby worsening brain damage. However, pericytes are often overlooked by researchers, and no review research has yet summarized the mechanism by which pericytes contribute to BBB dysfunction in CNS diseases. RESULTS: Therefore, this review explores the pathophysiology of BBB dysfunction in CNS diseases and provides a detailed account of the biological characteristics of pericytes, especially the controversy over their biomarkers. Subsequently, we review the role of pericytes in CNS diseases such as Alzheimer's disease, vascular dementia, multiple sclerosis, ischemic stroke, and hemorrhagic stroke, with a particular focus on the role of pericytes in BBB dysfunction. In addition, we also discuss treatments based on pericytes, such as regenerative medicine that induces pericyte differentiation and Pericyte-Extracellular Vesicles. CONCLUSIONS: This review aims to provide a more comprehensive understanding and guidance on the role of pericytes in BBB dysfunction in CNS diseases and serve clinical treatment.