The invention belongs to the fields of analytical chemistry and clinical medicine, and discloses a capric acid and prostaglandin E2 combination as a giant baby auxiliary diagnosis marker and the application thereof. The auxiliary diagnosis marker is a combination of micromolecular capric acid and prostaglandin E2, can be used for preparing a giant baby auxiliary diagnosis or monitoring kit, is relatively high in sensitivity and specificity and rapid in detection, and has a relatively high clinical application value.