OBJECTIVE To investigate the efficacy and safety of ropivacaine combined with oxycodone for the analgesia of iliac fascia nerve block in patients undergoing hip replacement. METHODS Sixty-six patients who underwent hip replacement at the Central Hospital of Enshi Tujia and Miao Autonomous Prefecture from October 2023 to April 2024 were selected and randomly divided into observation group and control group， with 33 cases in each group. Before induction of anesthesia， ultrasound-guided iliac fascial nerve block was performed. Patients in the observation group were treated with 0.33% ropivacaine+0.1 mg/kg oxycodone injection mixture 30 mL， and patients in the control group were treated with 0.33% ropivacaine injection 30 mL. The time of first postoperative rescue analgesia， 24 h postoperative analgesic drug consumption， sensory block and motor block effective and maintenance time， satisfaction degree， numerical rating scale （NRS） pain score， Ramsay sedation score， muscle strength score， heart rate （HR）， mean arterial pressure （MAP）， oxygen saturation（SpO2）， sleep score， anxiety score， and the occurrence of adverse reactions in the two groups were all recorded. RESULTS Compared with the control group， the first rescue analgesia time after operation was significantly prolonged in the observation group， and 24 h postoperative analgesic drug consumption after operation decreased； the effective time of sensory block was significantly shortened， and the maintenance time of sensory block was significantly prolonged， and the satisfaction score was higher； the NRS pain score after iliac fascia nerve block was lower， HR and MAP were lower， and the anxiety score and sleep score 24 and 48 h after operation were lower （P＜0.05）. In terms of safety， patients in both groups had adverse reactions after operation， such as hypertension， nausea， vomiting， and dizziness， but there was no significant difference in the incidence of adverse reactions between the two groups （P＞0.05）. CONCLUSIONS Oxycodone combined with ropivacaine shows good efficacy and safety for iliac fascial nerve block analgesia in patients undergoing hip replacement， can significantly prolong the analgesic time of ropivacaine， reduce postoperative analgesic drug consumption， improve the sleep quality of patients， and promote the rapid recovery of patients.