〔Abstract〕 Objective To investigate the effect of ropivacaine combined with hydrocortisone on ultrasound guided brachial plexus block and its analgesic effect during shoulder arthroscopic surgery. Methods A total of 90 patients who underwent shoulder arthroscopic surgery in Zhengzhou Orthopaedic Hospital from March 2020 to January 2023 were selected as the study subjects. They were divided into a control group and an observation group based on the odd even number method of admission order, with 45 patients in each group. The control group received ultrasound guided brachial plexus block with ropivacaine, while the observation group received additional intravenous infusion of hydrocortisone in addition to the control group. The nerve block effect, use of anesthetic drugs, postoperative pain perception and adverse reactions between the two groups of patients were compared. Results There was no significant difference in the onset time of motor and sensory block between the observation group and the control group (P > 0.05), but the duration was higher than that of the control group, and the difference was statistically significant (P < 0.05). The amount of propofol and remifentanil used in the observation group was less than that in the control group during the operation, and the amount of tramadol used for remedial analgesia after the operation was less than that in the control group, with statistical significance (P < 0.05). The pain visual analogue scale (VAS) scores of the observation group at 6h, 12h, 18h and 24h after surgery were lower than those of the control group, and the differences were statistically significant (P < 0.05). The incidence of adverse reactions in the observation group was lower than that in the control group, and the difference was statistically significant (P < 0.05). Conclusion The combination of ropivacaine and hydrocortisone for ultrasound guided brachial plexus block during shoulder arthroscopic surgery can prolong the duration of sensory and motor block, reduce patient pain perception, reduce the use of anesthesia and analgesics, and reduce the occurrence of adverse reactions.