Objective To explore the surgical techniques and safety of combined segment resection of inferior vena cava without reconstruction for retroperitoneal tumors. Methods The data of 27 patients with retroperitoneal tumors involving inferior vena cava admitted to the Department of Retroperitoneal Tumor Surgery of Peking University International Hospital from Mar. 2015 to Feb. 2020 were retrospectively analyzed. All the patients underwent combined segment resection of the inferior vena cava without reconstruction. The inferior vena cava was divided into 4 segments: segmentⅠ (from the bifurcation of the common iliac vein to 2 cm below the entrance of the renal vein), segmentⅡ (from 2 cm below the renal vein to 2 cm above the renal vein), segmentⅢ (from 2 cm above the renal vein to below the diaphragm) and segmentⅣ (supradiaphragmatic segment). According to the inferior vena cava segmentation and collateral circulation, the surgical plans were formulated, the related postoperative complications of the inferior vena cava resection were observed, and the preoperative and postoperative renal function indicators were recorded and compared. Results The surgery was successfully completed in all the 27 patients without operative death, with R0 resection in 22 cases and R1 resection in 5 cases, including 11 cases of segmentⅠ inferior vena cava resection, 5 cases of segmentⅡ, 6 cases of segment Ⅱ+Ⅲ, and 5 cases of segmentⅢ. Ten cases were combined with right nephrectomy, 4 cases with hepatometastasis resection, 3 cases with right hemicolectomy, 2 cases with small intestine partial resection, and 2 cases with right iliac artery artificial vessel reconstruction. The creatinine level of the patients with right nephrectomy was (58.1±14.5) μmol/L before operation, and was (63.1±16.2) μmol/L 2 weeks after operation, showing no significant difference (P>0.05). Six cases had moderate or large amount of ascites (the average drainage volume of ascites was more than 400 mL/d one week after operation), and 5 cases had lower extremity edema which gradually returned to normal about 2 weeks after operation; 4 cases had renal insufficiency after operation, and 2 of them recovered after short-term hemodialysis replacement therapy. Conclusion Retroperitoneal tumors can invade different parts of the inferior vena cava. Segment resection without reconstruction is safe and reliable when collateral circulation has been fully established or reconstruction is predictable. Accurate preoperative assessment can effectively guide the surgical approach and control the risk of postoperative complications.