The blood-brain barrier is a dynamic and complex neurovascular unit that protects neurons from somatic circulatory factors as well as regulates the internal environmental stability of the central nervous system. Endothelial glycocalyx is a critical component of an extended neurovascular unit that influences the structure of the blood-brain barrier and plays various physiological functions, including an important role in maintaining normal neuronal homeostasis. Specifically, glycocalyx acts in physical and charge barriers, mechanical transduction, regulation of vascular permeability, modulation of inflammatory response, and anticoagulation. Since intact glycocalyx is necessary to maintain the stability and integrity of the internal environment of the blood-brain barrier, damage to glycocalyx can lead to the dysfunction of the blood-brain barrier. This review discusses the role of glycocalyx in the context of the substantial literature regarding the blood-brain barrier research, in order to provide a theoretical basis for the diagnosis and treatment of neurological diseases as well as point to new breakthroughs and innovations in glycocalyx-dependent blood-brain barrier function. © 2020 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.