Objective:To retrospectively observe the effect of oxycodone on acute postoperative pain in patients undergoing thoracoscopic surgery.Methods:A retrospective analysis was conducted on the clinical data of 404 patients undergoing thoracoscopic thoracic surgery under combined general anesthesia at the Xiangya Hospital, Central South University from April 1, 2020 to September 30, 2021. They were divided into A group ( n=99, oxycodone group) and B group ( n=305, control group) based on whether oxycodone was used during the surgery. The two groups of patients were further matched 1∶1 using the nearest neighbor matching method. We compared the Visual Analogue Scale (VAS) of activity and resting pain and the incidence of moderate to severe pain between two groups of patients 24 hours after surgery, and observed the incidence and severity of pain related adverse reactions such as nausea, vomiting, itching, and dizziness. Resultsl:After matching the propensity scores of the two groups of patients, the balance was good ( SMD<0.20). There was no statistically significant difference between the groups in age, gender, body mass index, American Society of Anesthesiologist (ASA) grade, surgical time, intraoperative bleeding, and the use of antiemetics and analgesics during the perioperative period (all P>0.05). Compared with the control group, patients in the group A had a resting VAS [(2.03±1.61)points vs (1.62±1.31)points, P=0.049], and activity VAS [(4.13±1.72)points vs (3.51±1.79)points, P=0.013] was even lower, and the incidence of moderate to severe pain (VAS≥4) during activity was lower [59.6%(59/99) vs 37.4%(37/99), P=0.003]. There was no statistically significant difference in the incidence of analgesic related adverse reactions between the two groups ( P>0.05). Conclusions:Intravenous injection of oxycodone can effectively alleviate acute pain in patients undergoing thoracoscopic surgery within 24 hours, and reduce the incidence of moderate to severe pain during activity.