This section elaborates on the current status and hazards of gastric cancer and its peritoneal metastasis，and explains the importance and clinical significance of combined detection of serum tumor markers in the diagnosis of peritoneal metastasis from gastric cancer. Gastric cancer remains one of the most prevalent malignant tumors globally，imposing a heavy burden on public health due to its high morbidity and mortality rates. Traditional diagnostic methods for peritoneal metastasis，such as physical examination and routine imaging techniques，have limitations in sensitivity and specificity，especially for early or small-volume peritoneal metastases. In contrast ， serum tumor marker detection exhibits advantages of being non-invasive，convenient，and cost-effective，making it a potential supplementary or alternative diagnostic tool. However，the diagnostic value of single serum tumor marker detection is often restricted by low sensitivity or specificity. Thus，exploring the application value of combined detection of multiple serum tumor markers in the diagnosis of peritoneal metastasis from gastric cancer has become a research focus in clinical oncology，which is of great significance for optimizing the diagnostic workflow and guiding clinical practice.