[Objectives] To explore the clinical application of three-dimensional CT reconstruction and printing technology in the resection of complicated retroperitoneal tumors. [Methods] Thirteen patients with complicated retroperitoneal tumors treated at Guangdong Provincial Hospital of Traditional Chinese Medicine from July 2020 to November 2021 were retrospectively reviewed. Three-dimensional CT reconstruction and printing model were made from contrast-enhanced CT scans for each patient before surgery. The tumor location and size and its relation to the surrounding organs were analyzed according to the three-dimensional CT reconstruction and printing model. Simulated resection was performed, individualized treatment regimens were designed. Observe and record the consistency between the simulated operation scheme and the actual operation scheme, completed resection of tumor, combined resection of surrounding organs, maximum diameter of tumor, the tumor weight, operation time, intraoperative blood loss, postoperative hospital stay, pathological results, complications and follow up results. [Results] All the tumors were printed with the 3-dimensional model, which can display the location, anatomy, and relationship with surrounding blood vessels. The consistency proportion median between simulated surgery and the actual surgery was 13/13. Completed resection was successfully performed in all cases. Among the 13 patients, there were 3 cases of simple tumor resection and 10 cases of combined organ resection, total of 32 organs were resected. The median length of the resected tumor was 21.5(11.4, 29.9) cm. The median weight of the resected tumor was 4 130.0(585.5, 11 300.0) g. The median operation time was 193(154, 266) min, median intraoperative blood loss was 200(150, 600) mL, and the median postoperative hospital stay was 6(5, 7) d. Perioperative intestinal fistulas occurred in 1 patient. No perioperative death occurred. No recurrence or metastasis occurred during the 9(4, 15) months of follow-up. [Conclusion] Three-dimensional CT reconstruction can accurately display the anatomic relationship between tumors and their surrounding organs, effectively simulate complex retroperitoneal tumor resection. It is helpful for preoperative surgery design, accurate intraoperative navigation, and comparison of operative results.