The serotonin receptor (5-HT receptor) family comprises at least 14 subtypes, categorized into 7 classes (5-HT1 to 5-HT7). These receptors regulate cellular signal transduction through G protein-coupled receptors (GPCRs) or ion channel pathways. They are widely distributed in the central and peripheral nervous systems, modulating emotions, sleep, appetite, cognition, and gastrointestinal function. 5-HT receptors exhibit specific expression patterns in different brain regions and tissues, and their dysfunction or genetic variations are associated with various mental disorders (such as depression, anxiety), neurological diseases, and gastrointestinal functional disorders. Research on 5-HT receptors provides crucial targets in psychopharmacology, playing a vital role in the development of drugs for treating related diseases.