The pathogenesis of burning mouth syndrome (BMS) is not clear. Most scholars believe that primary BMS is a chronic neurological disease. Advanced diagnostic methods such as quantitative sensory testing (QST), trigeminal neuron electrophysiological recording and peripheral nerve blockade, structural analysis of epidermal nerve fiber density (ENFD), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) classify neuropathic pain in most BMS patients as peripheral or central. Hormone replacement, dopaminergic drugs and noninvasive neuromodulation may be new approaches to BMS based on its pathogenesis. This article reviews the clinical features, pathophysiological mechanism, new diagnostic methods and treatment of primary BMS and provides new ideas for the clinical diagnosis and treatment of BMS.