Postpartum depression is a common psychological abnormality during the puerperium, which seriously affects maternal and neonatal health. Esketamine, the S-enantiomer of ketamine, is twice as potent as ketamine and can be safely used for cesarean section and labor analgesia. However, it is not clear whether esketamine used for epidural labor analgesia can significantly reduce the incidence of postpartum depression. This study intends to explore the incidence of maternal prenatal depression and to investigate the effect of esketamine for epidural labor analgesia on postpartum depression and maternal and neonatal outcomes in parturients with prenatal depression through a multi-center, large-scale and high-quality clinical trail, in order to provide a clinical basis and theoretical basis for the application of esketamine used for epidural labor analgesia in postpartum depression and further reduce the incidence of postpartum depression, promote maternal and infant health, and ensure maternal and infant safety .