Objective: To determine the influence of preemptive analgesia with oxycodone hydrochloride on stress hormone level of geriatric patients undergoing gastrointestinal surgery, and evaluate the analgesic effect. Study Design: Rrandomised controlled trial. Place and Duration of Study: Department of Anaesthesiology, Baoding First Central Hospital, from January to December 2017. Methodology: Geriatric patients who were to undergo gastrointestinal surgery were classified into observation group and control group of 30 patients each. For the observation group, intravenous injection of 0.1mg/kg oxycodone hydrochloride injection was conducted 10 mins before anesthesia induction. For the control group, intravenous injection of 10 ml normal saline was conducted. Eight ml of venous blood was drawn 10 mins before injection (T0), after operation (T1), 2 hours after operation (T2), 6 hours after operation (T3), and 24 hours after operation (T4). Serum concentration of cortisol, epinephrine, noradrenaline was determined after the completion of surgery (T1), 2-hour after surgery (T2), 6-hour after surgery (T3) and 24-hour after surgery (T4). for both groups. Visual analogue scale (VAS) score was used for assessment of pain when the surgery was completed; and after the surgery, was compared for both groups. Results: Serum concentrations of epinephrine and noradrenaline in observation group were significantly reduced at T1 and T2 (p <0.05), and serum concentrations of cortisol and glucose were significantly reduced at T1, T2 and T3 (p <0.05). At 2 and 6-hours after operation, the VAS score was significantly lower than that of the control group (p<0.05). Conclusion: Giving oxycodone hydrochloride to geriatric patients receiving gastrointestinal surgery can reduce stress hormone release in the postoperative period, and can facilitate postoperative recovery.