Objective To retrospectively analyze the analgesic effect and cost-effectiveness of combined analgesia versus intermittent analgesia for patients underwent retroperitoneal laparoscopic surgery. Methods We retrospectively collected clinical parameters and outcomes of analgesic effect from patients who underwent retroperitoneal laparoscopic surgery. Included patients were divided into two groups: local injection of ropivacaine combined with intermittent administration with analgesic via intravenous injection and intermittent administration with analgesic via intravenous injection only. Visual analogue scale (VAS) at different time points (2 h, 4 h, 6 h, 12 h, 24 h), usage of postoperative non-steroidal anti-inflammatory drugs (NSAIDs), adverse events, costs and other information were collected and assessed for further analysis of analgesic effect and cost-effectiveness. Results A total of 80 patients were enrolled in this study, each group consists of 40 patients. The results of this study found that VAS scores at 2 h and 4 h after operation in the combined analgesic group were significantly lower than that in the intermittent intravenous analgesia group (P<0.05), while there were no significant differences between the two groups in VAS scores at 6, 12 and 24 h after operation. The usage of NSAIDs were significantly lower in the combined group than intermittent group (P<0.05). The effective rate in the combined group was significantly higher than that in the intermittent group (P<0.05). The average cost of postoperative hospitalization and postoperative analgesic of the two groups were similar (allP values >0.05), and cost-effectiveness evaluation of the combined analgesia group was better than that of intermittent group. Conclusion Compared to intermittent administration with analgesic via intravenous injection, subcutaneous injection of ropivacaine hydrochloride combined with intermittent intravenous injection of parecoxib in patients underwent retroperitoneal laparoscopic surgery significantly could alleviate patients' painful complaints and reduce the postoperative usage of NSAIDs without increasing adverse events. Furthermore, the combination strategy has a lower cost-effectiveness ratio than intermittent group, which represents economic advantages.