Objective: To investigate the effects of magnesium sulfate wet compress applied during the second stage of labor in vaginal delivery on maternal and neonatal outcomes, and to provide evidence for perineal protection in midwifery practice. Methods: In this retrospective cohort study, 117 women who delivered vaginally between September and October 2025 at the study center were enrolled. According to perineal management during the second stage of labor, participants were assigned to the magnesium sulfate wet compress group or the control group. Maternal outcomes (labor duration, perineal laceration rate, NRS pain score, perineal edema, and postpartum cold compress requirement) and neonatal outcomes (body length, birth weight, Apgar score, and transfer rate) were compared between groups. Results: There were no statistically significant differences in baseline characteristics between the two groups (P > 0.05). Compared with the control group, parturients in the observation group had significantly lower pain scores at 2 hours postpartum, as well as lower incidences of perineal edema and reduced demand for cold compress therapy; moreover, the rates of perineal laceration and episiotomy were significantly decreased (P < 0.05). No statistically significant differences were observed between the two groups with respect to neonatal length, birth weight, Apgar score, or neonatal transfer rate (P > 0.05). Conclusion: Magnesium sulfate wet compress during the second stage of labor is a safe and feasible intervention that effectively reduces perineal pain, edema, and birth-related perineal trauma without compromising neonatal outcomes. Larger randomized controlled studies are needed to confirm these findings.