To analyze the effect of ultrasound-guided lumbar quadratus block on oxidative stress and immune function of patients after gynecological laparoscopic surgery. Methods: 70 patients with gynecological laparoscopic surgery were selected and were divided into two groups according to random number table from March 2016 to May 2019. All patients had received general anesthesia induction during operation, the patients in the observation group had received lumbar quadratus block under ultrasound guidance, while the patients in the control group had received horizontal abdominal and transverse muscle block. All patients in the two groups were given morphine controlled analgesia intravenously after operation. The operation relevant index, cumulative dosage of morphine at each time point, immune function, and oxidative stress index of the patients were compared between the two groups. Results: There were no significant difference in operation time, anesthesia time, nerve block time, and bleeding volume of patients between groups (P＞0.05). The cumulative dosage of morphine of patients at 6,12,24 or 48 hours after operation in the observation group was significant lower than that of patients in the control group. The levels of MAOA of patients at 6,12 or 24 hours after operation in the observation group was significant lower than those in the control group after operation, while the levels of SOD and GSH-Px of patients at 6,12 or 24 hours after operation in the observation group were significant higher (all P＜0.05). At 12 and 24 hours after operation, CD4+ and CD3+ levels of patients in the observation group were significant higher than those of patients in the control group, and at 12 hours after operation, CD4+/CD8+ value of patients in the observation group was significant higher than that of patients in the control group.There were no significant difference in oxidative stress indexes of patients at 48 hours after operation between the two groups (P＞0.05). There was no any patient with adverse reactions, such as respiratory depression, skin itching, digestive tract symptoms, and excessive sedation occurred in both groups. Conclusion: Ultrasound-guided lumbar quadratus block has good analgesic effect, which will help to improve the oxidative stress and immune function of patients after gynecological laparoscopic surgery.