Abstract: Gastric cancer, a highly malignant tumor, has seen a persistent rise in global incidence in recent years. Claudin 18.2, a protein with highly specific expression in gastric cancer, has emerged as a prominent research target in therapeutic development. The overexpression of Claudin 18.2 in gastric cancer cells and its abnormal surface exposure provide novel opportunities for targeted and immunotherapeutic interventions. Therapeutic approaches targeting Claudin 18.2 have shown promising initial results in clinical trials, primarily including monoclonal antibodies and chimeric antigen receptor T-cell therapies. The authors systematically summarize the biological characteristics, mechanism of action, clinical research progress, and future treatment prospects and challenges of Claudin 18.2.